You can declare class-in-class (like functions).
Look at this example:
class Foo
$name = 'the foo'
class Bar
$name = 'the bar'
endclass
endclass
println(Foo()->name)
println(Bar()->name)
output:
the foo
the bar
Also look at this example:
class First
$name = 'first'
class Second
$name = 'second'
class Last
$name = 'last'
endclass
class Person
$name = 'person'
endclass
endclass
$the_second = Second()
endclass
println(First()->name)
println(Second()->name)
println(Last()->name)
println(Person()->name)
println(First()->the_second->name)
output:
first
second
last
person
second