Documentation for method generate_mixin assembled from the following pages:

Role: Metamodel::Mixins §

From Metamodel::Mixins

(Metamodel::Mixins) method generate_mixin §

method generate_mixin($obj, @roles)

Creates a new mixin metaobject that inherits from $obj and does each of the roles in @roles. This is then composed and has its mixin attribute set (if any exists) before getting returned.

While this generates a new mixin type, this doesn't actually mix it into $obj; if that is what you intend to do, use the mixin metamethod instead.