code: def parameters(self):
          
          pyname = self.pyname
          if isinstance(pyname, pynames.ImportedName):
              pyname = pyname._get_imported_pyname()
          if isinstance(pyname, pynames.DefinedName):
              pyobject = pyname.get_object()
              if isinstance(pyobject, pyobjects.AbstractFunction):
                  return pyobject.get_param_names()
docs: The names of the parameters the function takes.
  
          Returns None if this completion is not a function.