null : Variable to assign key to * 'byRef' => false : Whether to assign value by reference * 'stmts' => array(): Statements * @param array $attributes Additional attributes */ public function __construct(Node\Expr $expr, Node\Expr $valueVar, array $subNodes = array(), array $attributes = array()) { parent::__construct( $subNodes + array( 'keyVar' => null, 'byRef' => false, 'stmts' => array(), ), $attributes ); $this->expr = $expr; $this->valueVar = $valueVar; } }