code: def check_docstring(cls):
          
          docstring = inspect.getdoc(cls)
          if not docstring:
              breadcrumbs = " -> ".join(t.__name__ for t in inspect.getmro(cls)[:-1][::-1])
              msg = "docstring required for plugin '%s' (%s, defined in %s)"
              args = (cls.__name__, breadcrumbs, cls.__module__)
              raise InternalCashewException(msg % args)
  
          max_line_length = cls._class_settings.get('max-docstring-length')
          if max_line_length:
              for i, line in enumerate(docstring.splitlines()):
                  if len(line) > max_line_length:
                      msg = "docstring line %s of %s is %s chars too long" 
                      args = (i, cls.__name__, len(line) - max_line_length)
                      raise Exception(msg % args)
  
          return docstring
docs: Asserts that the class has a docstring, returning it if successful.