Is there any way to specify the run stage for a puppet class I wish to include in several other classes?

run_stages.pp

Question:

Is there a way to make myclass run before my other
classes without defining explicit relationships?

==================================================

site.pp:

stage{ 'first': }
Stage['first'] -> Stage['main']

--------------------------------------------------

myclass/manifests/init.pp:

class myclass {

    define something_useful {}
}
---------------------------------------------------

A/manifests/init.pp:

class A {
   include myclass
}
---------------------------------------------------

B/manifests/init.pp:

class B {
   include myclass
}
---------------------------------------------------

C/manifests/init.pp:

class C {
   include myclass
}
---------------------------------------------------