Removing from list nodes
-----
<?php $foo; $bar; $baz;
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array_splice($stmts, 1, 1, []);
-----
<?php $foo; $baz;
-----
<?php
function foo(
    $a,
    $b,
    $c
) {}
-----
array_pop($stmts[0]->params);
-----
<?php
function foo(
    $a,
    $b
) {}
-----
<?php
function foo(
    $a,
    $b,
    $c
) {}
-----
array_pop($stmts[0]->params);
$stmts[0]->params[] = new Node\Param(new Expr\Variable('x'));
$stmts[0]->params[] = new Node\Param(new Expr\Variable('y'));
-----
<?php
function foo(
    $a,
    $b,
    $x,
    $y
) {}
-----
<?php
function test(): A
|B
|C {}
-----
array_pop($stmts[0]->returnType->types);
-----
<?php
function test(): A
|B {}