Modifier change
-----
<?php
class Foo {}
abstract class Bar {
    const
    FOO = 42;

    var $foo
    = 24;

    public function
    foo() {}
}
-----
$stmts[0]->flags = Stmt\Class_::MODIFIER_ABSTRACT;
$stmts[1]->flags = 0;
$stmts[1]->stmts[0]->flags = Stmt\Class_::MODIFIER_PRIVATE;
$stmts[1]->stmts[1]->flags = Stmt\Class_::MODIFIER_PROTECTED;
$stmts[1]->stmts[2]->flags |= Stmt\Class_::MODIFIER_FINAL;
-----
<?php
abstract class Foo {}
class Bar {
    private const
    FOO = 42;

    protected $foo
    = 24;

    public final function
    foo() {}
}