docs: def validate(self, handler):
          """Validate the plugin, each plugin must have the following:
              1) The worker class must have an execute method: execute(self, input_data).
              2) The worker class must have a dependencies list (even if it's empty).
              3) The file must have a top level test() method.
  
          Args:
              handler: the loaded plugin.
          """
  
          # Check for the test method first
          test_method = self.plugin_test_validation(handler)
          if not test_method:
              return None
  
          # Here we iterate through the classes found in the module and pick
          # the first one that satisfies the validation
          for name, plugin_class in inspect.getmembers(handler, inspect.isclass):
              if self.plugin_class_validation(plugin_class):
                  return {'class':plugin_class, 'test':test_method}
  
          # If we're here the plugin didn't pass validation
          print 'Failure for plugin: %s' % (handler.__name__)
          print 'Validation Error: Worker class is required to have a dependencies list and an execute method'
          return None