Enum
-----
<?php

enum A implements B
{
    case X;
    case Y;

    public function foo() {}
}

enum B: int {
    case X = 1;
    case Y = 2;
}

enum C: string implements D {
    case Z = 'A';
}

enum D: \Foo\Bar {}
-----
enum A implements B
{
    case X;
    case Y;
    public function foo()
    {
    }
}
enum B : int
{
    case X = 1;
    case Y = 2;
}
enum C : string implements D
{
    case Z = 'A';
}
enum D : \Foo\Bar
{
}