问如何编写木偶类对另一个类状态的依赖

EN

class my::main {
   require my::module::precheck
   # I want to execute installpackage if precheck is succeed.
   require my::module::installpackage
}

class my::module::precheck {
       if $facts['osfamily'] == 'redhat' {
        if versioncmp($facts['operatingsystemmajrelease'], '7') >= 0 {
            notify {"osrelease":
                message => "${::operatingsystemmajrelease} is good to install myapp."
            }
        }
        else {
            fail("myapp is not supported on this OS release")
        }
    }
    else {
         fail("myapp is not supported on ${::osfamily}.")
    }
}