new_contents: 
  # tested classes
  from cern.pymad.abc.interface import Interface
  
  # test utilities
  import unittest
  from inspect import getdoc
  from abc import abstractmethod
  
  #
  class AbstractBase(Interface):
      @abstractmethod
      def foo(self):
          """
          Dummy documentation for AbstractBase.foo
          """
          pass
  
      @abstractmethod
      def bar(self):
          """
          Dummy documentation for AbstractBase.bar
          """
          pass
  
  def _bar(self):
      """
      Dummy documentation for Derived.bar
      """
      pass
  
  class Derived(AbstractBase):
      def foo(self):
          pass
  
      bar = _bar
  
  class TestInterface(unittest.TestCase):
      def test_method_doc(self):
          self.assertEqual(
                  getdoc(Derived.foo),
                  getdoc(AbstractBase.foo))
          self.assertTrue(
                  getdoc(Derived.bar).startswith(getdoc(_bar)))
          self.assertTrue(
                  getdoc(Derived.bar).endswith(getdoc(AbstractBase.bar)))
  
  
subject: Add test for Interface base class