title: pytest-mock: Mock an abstract class
body: <p>I'm trying to make the following code work:</p>
  
  <pre><code>from pytest_mock import mocker
  
  class TestClass(mocker):
    def setup_method(self):
      self.some_mock = SomeAbstractClass()
      self.testsubject = ClassThatIsBeingTested(self.some_mock)
  
    def test_1(self):
      mocker.patch(self.some_mock, 'some_function', return_value=5)
      assert 5 == self.testsubject.function_that_internally_uses_the_mock()
  </code></pre>
  
  <p>But I get a <code>TypeError</code> for trying to instantiate an abstract class.  </p>
  
  <p>How can I mock <code>SomeAbstractClass</code>?</p>