diff --git a/lib/PhpParser/Builder/Class_.php b/lib/PhpParser/Builder/Class_.php
index 56221e6..c247787 100644
--- a/lib/PhpParser/Builder/Class_.php
+++ b/lib/PhpParser/Builder/Class_.php
@@ -6,20 +6,18 @@ use PhpParser;
 use PhpParser\Node\Name;
 use PhpParser\Node\Stmt;
 
-class Class_ extends PhpParser\BuilderAbstract
+class Class_ extends Declaration
 {
     protected $name;
 
-    protected $extends;
-    protected $implements;
-    protected $type;
+    protected $extends = null;
+    protected $implements = array();
+    protected $type = 0;
 
-    protected $uses;
-    protected $constants;
-    protected $properties;
-    protected $methods;
-
-    protected $attributes;
+    protected $uses = array();
+    protected $constants = array();
+    protected $properties = array();
+    protected $methods = array();
 
     /**
      * Creates a class builder.
@@ -28,13 +26,6 @@ class Class_ extends PhpParser\BuilderAbstract
      */
     public function __construct($name) {
         $this->name = $name;
-
-        $this->type = 0;
-        $this->extends = null;
-        $this->implements = array();
-
-        $this->uses = $this->constants = $this->properties = $this->methods = array();
-        $this->attributes = array();
     }
 
     /**
@@ -42,7 +33,7 @@ class Class_ extends PhpParser\BuilderAbstract
      *
      * @param Name|string $class Name of class to extend
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function extend($class) {
         $this->extends = $this->normalizeName($class);
@@ -56,7 +47,7 @@ class Class_ extends PhpParser\BuilderAbstract
      * @param Name|string $interface Name of interface to implement
      * @param Name|string $...       More interfaces to implement
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function implement() {
         foreach (func_get_args() as $interface) {
@@ -69,7 +60,7 @@ class Class_ extends PhpParser\BuilderAbstract
     /**
      * Makes the class abstract.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeAbstract() {
         $this->setModifier(Stmt\Class_::MODIFIER_ABSTRACT);
@@ -80,7 +71,7 @@ class Class_ extends PhpParser\BuilderAbstract
     /**
      * Makes the class final.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeFinal() {
         $this->setModifier(Stmt\Class_::MODIFIER_FINAL);
@@ -93,7 +84,7 @@ class Class_ extends PhpParser\BuilderAbstract
      *
      * @param Stmt|PhpParser\Builder $stmt The statement to add
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function addStmt($stmt) {
         $stmt = $this->normalizeNode($stmt);
@@ -115,36 +106,6 @@ class Class_ extends PhpParser\BuilderAbstract
         return $this;
     }
 
-    /**
-     * Adds multiple statements.
-     *
-     * @param array $stmts The statements to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addStmts(array $stmts) {
-        foreach ($stmts as $stmt) {
-            $this->addStmt($stmt);
-        }
-
-        return $this;
-    }
-
-    /**
-     * Sets doc comment for the property.
-     *
-     * @param PhpParser\Comment\Doc|string $docComment Doc comment to set
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function setDocComment($docComment) {
-        $this->attributes = array(
-            'comments' => array($this->normalizeDocComment($docComment))
-        );
-
-        return $this;
-    }
-
     /**
      * Returns the built class node.
      *
diff --git a/lib/PhpParser/Builder/Declaration.php b/lib/PhpParser/Builder/Declaration.php
new file mode 100644
index 0000000..f6a322c
--- /dev/null
+++ b/lib/PhpParser/Builder/Declaration.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace PhpParser\Builder;
+
+use PhpParser;
+use PhpParser\Node;
+use PhpParser\Node\Stmt;
+
+abstract class Declaration extends PhpParser\BuilderAbstract
+{
+    protected $attributes = array();
+
+    abstract public function addStmt($stmt);
+
+    /**
+     * Adds multiple statements.
+     *
+     * @param array $stmts The statements to add
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function addStmts(array $stmts) {
+        foreach ($stmts as $stmt) {
+            $this->addStmt($stmt);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets doc comment for the declaration.
+     *
+     * @param PhpParser\Comment\Doc|string $docComment Doc comment to set
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function setDocComment($docComment) {
+        $this->attributes['comments'] = array(
+            $this->normalizeDocComment($docComment)
+        );
+
+        return $this;
+    }
+}
\ No newline at end of file
diff --git a/lib/PhpParser/Builder/FunctionLike.php b/lib/PhpParser/Builder/FunctionLike.php
new file mode 100644
index 0000000..35646a3
--- /dev/null
+++ b/lib/PhpParser/Builder/FunctionLike.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace PhpParser\Builder;
+
+use PhpParser;
+use PhpParser\Node;
+use PhpParser\Node\Stmt;
+
+abstract class FunctionLike extends Declaration
+{
+    protected $returnByRef = false;
+    protected $params = array();
+
+    /**
+     * Make the function return by reference.
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function makeReturnByRef() {
+        $this->returnByRef = true;
+
+        return $this;
+    }
+
+    /**
+     * Adds a parameter.
+     *
+     * @param Node\Param|Param $param The parameter to add
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function addParam($param) {
+        $param = $this->normalizeNode($param);
+
+        if (!$param instanceof Node\Param) {
+            throw new \LogicException(sprintf('Expected parameter node, got "%s"', $param->getType()));
+        }
+
+        $this->params[] = $param;
+
+        return $this;
+    }
+
+    /**
+     * Adds multiple parameters.
+     *
+     * @param array $params The parameters to add
+     *
+     * @return $this The builder instance (for fluid interface)
+     */
+    public function addParams(array $params) {
+        foreach ($params as $param) {
+            $this->addParam($param);
+        }
+
+        return $this;
+    }
+}
\ No newline at end of file
diff --git a/lib/PhpParser/Builder/Function_.php b/lib/PhpParser/Builder/Function_.php
index da2d21e..374f315 100644
--- a/lib/PhpParser/Builder/Function_.php
+++ b/lib/PhpParser/Builder/Function_.php
@@ -6,14 +6,10 @@ use PhpParser;
 use PhpParser\Node;
 use PhpParser\Node\Stmt;
 
-class Function_ extends PhpParser\BuilderAbstract
+class Function_ extends FunctionLike
 {
     protected $name;
-
-    protected $returnByRef;
-    protected $params;
-    protected $stmts;
-    protected $attributes;
+    protected $stmts = array();
 
     /**
      * Creates a function builder.
@@ -22,56 +18,6 @@ class Function_ extends PhpParser\BuilderAbstract
      */
     public function __construct($name) {
         $this->name = $name;
-
-        $this->returnByRef = false;
-        $this->params = array();
-        $this->stmts = array();
-        $this->attributes = array();
-    }
-
-    /**
-     * Make the function return by reference.
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function makeReturnByRef() {
-        $this->returnByRef = true;
-
-        return $this;
-    }
-
-    /**
-     * Adds a parameter.
-     *
-     * @param Node\Param|Param $param The parameter to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addParam($param) {
-        $param = $this->normalizeNode($param);
-
-        if (!$param instanceof Node\Param) {
-            throw new \LogicException(sprintf('Expected parameter node, got "%s"', $param->getType()));
-        }
-
-        $this->params[] = $param;
-
-        return $this;
-    }
-
-    /**
-     * Adds multiple parameters.
-     *
-     * @param array $params The parameters to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addParams(array $params) {
-        foreach ($params as $param) {
-            $this->addParam($param);
-        }
-
-        return $this;
     }
 
     /**
@@ -79,7 +25,7 @@ class Function_ extends PhpParser\BuilderAbstract
      *
      * @param Node|PhpParser\Builder $stmt The statement to add
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function addStmt($stmt) {
         $this->stmts[] = $this->normalizeNode($stmt);
@@ -87,36 +33,6 @@ class Function_ extends PhpParser\BuilderAbstract
         return $this;
     }
 
-    /**
-     * Adds multiple statements.
-     *
-     * @param array $stmts The statements to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addStmts(array $stmts) {
-        foreach ($stmts as $stmt) {
-            $this->addStmt($stmt);
-        }
-
-        return $this;
-    }
-
-    /**
-     * Sets doc comment for the function.
-     *
-     * @param PhpParser\Comment\Doc|string $docComment Doc comment to set
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function setDocComment($docComment) {
-        $this->attributes = array(
-            'comments' => array($this->normalizeDocComment($docComment))
-        );
-
-        return $this;
-    }
-
     /**
      * Returns the built function node.
      *
diff --git a/lib/PhpParser/Builder/Interface_.php b/lib/PhpParser/Builder/Interface_.php
index 84be7a0..18afaaa 100644
--- a/lib/PhpParser/Builder/Interface_.php
+++ b/lib/PhpParser/Builder/Interface_.php
@@ -6,13 +6,12 @@ use PhpParser;
 use PhpParser\Node\Name;
 use PhpParser\Node\Stmt;
 
-class Interface_ extends PhpParser\BuilderAbstract
+class Interface_ extends Declaration
 {
     protected $name;
-    protected $extends;
-    protected $constants;
-    protected $methods;
-    protected $attributes;
+    protected $extends = array();
+    protected $constants = array();
+    protected $methods = array();
 
     /**
      * Creates an interface builder.
@@ -21,9 +20,6 @@ class Interface_ extends PhpParser\BuilderAbstract
      */
     public function __construct($name) {
         $this->name = $name;
-        $this->extends = array();
-        $this->constants = $this->methods = array();
-        $this->attributes = array();
     }
 
     /**
@@ -32,7 +28,7 @@ class Interface_ extends PhpParser\BuilderAbstract
      * @param Name|string $interface Name of interface to extend
      * @param Name|string $...       More interfaces to extend
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function extend() {
         foreach (func_get_args() as $interface) {
@@ -47,7 +43,7 @@ class Interface_ extends PhpParser\BuilderAbstract
      *
      * @param Stmt|PhpParser\Builder $stmt The statement to add
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function addStmt($stmt) {
         $stmt = $this->normalizeNode($stmt);
@@ -72,37 +68,7 @@ class Interface_ extends PhpParser\BuilderAbstract
     }
 
     /**
-     * Adds multiple statements.
-     *
-     * @param array $stmts The statements to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addStmts(array $stmts) {
-        foreach ($stmts as $stmt) {
-            $this->addStmt($stmt);
-        }
-
-        return $this;
-    }
-
-    /**
-     * Sets doc comment for the property.
-     *
-     * @param PhpParser\Comment\Doc|string $docComment Doc comment to set
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function setDocComment($docComment) {
-        $this->attributes = array(
-            'comments' => array($this->normalizeDocComment($docComment))
-        );
-
-        return $this;
-    }
-
-    /**
-     * Returns the built class node.
+     * Returns the built interface node.
      *
      * @return Stmt\Interface_ The built interface node
      */
diff --git a/lib/PhpParser/Builder/Method.php b/lib/PhpParser/Builder/Method.php
index 468ed3d..b3ab60d 100644
--- a/lib/PhpParser/Builder/Method.php
+++ b/lib/PhpParser/Builder/Method.php
@@ -6,15 +6,11 @@ use PhpParser;
 use PhpParser\Node;
 use PhpParser\Node\Stmt;
 
-class Method extends PhpParser\BuilderAbstract
+class Method extends FunctionLike
 {
     protected $name;
-
-    protected $type;
-    protected $returnByRef;
-    protected $params;
-    protected $stmts;
-    protected $attributes;
+    protected $type = 0;
+    protected $stmts = array();
 
     /**
      * Creates a method builder.
@@ -23,18 +19,12 @@ class Method extends PhpParser\BuilderAbstract
      */
     public function __construct($name) {
         $this->name = $name;
-
-        $this->type = 0;
-        $this->returnByRef = false;
-        $this->params = array();
-        $this->stmts = array();
-        $this->attributes = array();
     }
 
     /**
      * Makes the method public.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makePublic() {
         $this->setModifier(Stmt\Class_::MODIFIER_PUBLIC);
@@ -45,7 +35,7 @@ class Method extends PhpParser\BuilderAbstract
     /**
      * Makes the method protected.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeProtected() {
         $this->setModifier(Stmt\Class_::MODIFIER_PROTECTED);
@@ -56,7 +46,7 @@ class Method extends PhpParser\BuilderAbstract
     /**
      * Makes the method private.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makePrivate() {
         $this->setModifier(Stmt\Class_::MODIFIER_PRIVATE);
@@ -67,7 +57,7 @@ class Method extends PhpParser\BuilderAbstract
     /**
      * Makes the method static.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeStatic() {
         $this->setModifier(Stmt\Class_::MODIFIER_STATIC);
@@ -78,7 +68,7 @@ class Method extends PhpParser\BuilderAbstract
     /**
      * Makes the method abstract.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeAbstract() {
         if (!empty($this->stmts)) {
@@ -94,7 +84,7 @@ class Method extends PhpParser\BuilderAbstract
     /**
      * Makes the method final.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeFinal() {
         $this->setModifier(Stmt\Class_::MODIFIER_FINAL);
@@ -102,57 +92,12 @@ class Method extends PhpParser\BuilderAbstract
         return $this;
     }
 
-    /**
-     * Make the method return by reference.
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function makeReturnByRef() {
-        $this->returnByRef = true;
-
-        return $this;
-    }
-
-    /**
-     * Adds a parameter.
-     *
-     * @param Node\Param|Param $param The parameter to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addParam($param) {
-        $param = $this->normalizeNode($param);
-
-        if (!$param instanceof Node\Param) {
-            throw new \LogicException(sprintf('Expected parameter node, got "%s"', $param->getType()));
-        }
-
-        $this->params[] = $param;
-
-        return $this;
-    }
-
-    /**
-     * Adds multiple parameters.
-     *
-     * @param array $params The parameters to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addParams(array $params) {
-        foreach ($params as $param) {
-            $this->addParam($param);
-        }
-
-        return $this;
-    }
-
     /**
      * Adds a statement.
      *
      * @param Node|PhpParser\Builder $stmt The statement to add
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function addStmt($stmt) {
         if (null === $this->stmts) {
@@ -164,36 +109,6 @@ class Method extends PhpParser\BuilderAbstract
         return $this;
     }
 
-    /**
-     * Adds multiple statements.
-     *
-     * @param array $stmts The statements to add
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function addStmts(array $stmts) {
-        foreach ($stmts as $stmt) {
-            $this->addStmt($stmt);
-        }
-
-        return $this;
-    }
-
-    /**
-     * Sets doc comment for the method.
-     *
-     * @param PhpParser\Comment\Doc|string $docComment Doc comment to set
-     *
-     * @return self The builder instance (for fluid interface)
-     */
-    public function setDocComment($docComment) {
-        $this->attributes = array(
-            'comments' => array($this->normalizeDocComment($docComment))
-        );
-
-        return $this;
-    }
-
     /**
      * Returns the built method node.
      *
diff --git a/lib/PhpParser/Builder/Param.php b/lib/PhpParser/Builder/Param.php
index a5d2960..af910c2 100644
--- a/lib/PhpParser/Builder/Param.php
+++ b/lib/PhpParser/Builder/Param.php
@@ -9,9 +9,9 @@ class Param extends PhpParser\BuilderAbstract
 {
     protected $name;
 
-    protected $default;
-    protected $type;
-    protected $byRef;
+    protected $default = null;
+    protected $type = null;
+    protected $byRef = false;
 
     /**
      * Creates a parameter builder.
@@ -20,10 +20,6 @@ class Param extends PhpParser\BuilderAbstract
      */
     public function __construct($name) {
         $this->name = $name;
-
-        $this->default = null;
-        $this->type = null;
-        $this->byRef = false;
     }
 
     /**
@@ -31,7 +27,7 @@ class Param extends PhpParser\BuilderAbstract
      *
      * @param mixed $value Default value to use
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function setDefault($value) {
         $this->default = $this->normalizeValue($value);
@@ -44,7 +40,7 @@ class Param extends PhpParser\BuilderAbstract
      *
      * @param string|Node\Name $type Type hint to use
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function setTypeHint($type) {
         if ($type === 'array' || $type === 'callable') {
@@ -59,7 +55,7 @@ class Param extends PhpParser\BuilderAbstract
     /**
      * Make the parameter accept the value by reference.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeByRef() {
         $this->byRef = true;
diff --git a/lib/PhpParser/Builder/Property.php b/lib/PhpParser/Builder/Property.php
index a65ad52..2d59d4c 100644
--- a/lib/PhpParser/Builder/Property.php
+++ b/lib/PhpParser/Builder/Property.php
@@ -9,9 +9,9 @@ class Property extends PhpParser\BuilderAbstract
 {
     protected $name;
 
-    protected $type;
-    protected $default;
-    protected $attributes;
+    protected $type = 0;
+    protected $default = null;
+    protected $attributes = array();
 
     /**
      * Creates a property builder.
@@ -20,16 +20,12 @@ class Property extends PhpParser\BuilderAbstract
      */
     public function __construct($name) {
         $this->name = $name;
-
-        $this->type = 0;
-        $this->default = null;
-        $this->attributes = array();
     }
 
     /**
      * Makes the property public.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makePublic() {
         $this->setModifier(Stmt\Class_::MODIFIER_PUBLIC);
@@ -40,7 +36,7 @@ class Property extends PhpParser\BuilderAbstract
     /**
      * Makes the property protected.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeProtected() {
         $this->setModifier(Stmt\Class_::MODIFIER_PROTECTED);
@@ -51,7 +47,7 @@ class Property extends PhpParser\BuilderAbstract
     /**
      * Makes the property private.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makePrivate() {
         $this->setModifier(Stmt\Class_::MODIFIER_PRIVATE);
@@ -62,7 +58,7 @@ class Property extends PhpParser\BuilderAbstract
     /**
      * Makes the property static.
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function makeStatic() {
         $this->setModifier(Stmt\Class_::MODIFIER_STATIC);
@@ -75,7 +71,7 @@ class Property extends PhpParser\BuilderAbstract
      *
      * @param mixed $value Default value to use
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function setDefault($value) {
         $this->default = $this->normalizeValue($value);
@@ -88,7 +84,7 @@ class Property extends PhpParser\BuilderAbstract
      *
      * @param PhpParser\Comment\Doc|string $docComment Doc comment to set
      *
-     * @return self The builder instance (for fluid interface)
+     * @return $this The builder instance (for fluid interface)
      */
     public function setDocComment($docComment) {
         $this->attributes = array(