The class that implements any class that inherits from
AbstractTranslet, i.e. any translet. Methods in this
class may be of the following kinds:
1. Main method: applyTemplates, implemented by intances of
MethodGenerator.
2. Named methods: for named templates, implemented by instances
of NamedMethodGenerator.
3. Rt methods: for result tree fragments, implemented by
instances of RtMethodGenerator.