<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def check_docstring(self, method):
        '''All methods should have a docstring.'''
        mn = method.__name__
        if method.__doc__ is None:
            return ['Missing docstring for method "{}"'.format(mn)]