Create an object that can be used to make an extended version of a methodSource:
Creates an object of class
MethodExtension, which when added to a
Method creates an
a short name identifier. Must be alphanumeric.
a longer, human readable label that can have other characters such as spaces, hyphens, etc.
a function with arguments "model", "draw", "out", and "base_method". This will become the function
ExtendedMethodobject that is created.
This class inherits from the