[Twisted-Python] twisted.plugin plugin framework

[Nathaniel Haggard]

1.  What is/was the purpose of twisted.plugin?  

2.  "mypkg" is a directory containing __init__.py

__init__.py contains:

import twisted.plugin
import zope.interface as z
import twisted.plugin as p

class Beta:
        z.implements(p.IPlugin)

class Gamma:
        """This is the doc string"""

        __implements__ = p.IPlugin

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

Trying to load the package with getPlugins returns an empty generator
as far as I can tell


import twisted.plugin
import mypkg

l = twisted.plugin.getPlugins(twisted.plugin.IPlugin, mypkg)
print dir(l)
for i in l:
        .....

Actually twisted.plugin.getCache doesn't return anything for
getPlugins to get.  Am I setting up the package incorrectly?