def __call__(self,*args):
        '''
        Returns meaningless output no matter what the input(s) is.  If no input,
        returns None.  Otherwise, returns an array of NaNs (or a single NaN) of
        the same size as the first input.
        '''
        if len(args) == 0:
            return None
        else:
            arg = args[0]
            if hasattr(arg,'shape'):
                return np.zeros_like(arg) + np.nan
            else:
                return np.nan
def __call__ ( self , * args ) : if len ( args ) == 0 : return None else : arg = args [ 0 ] if hasattr ( arg , 'shape' ) : return np . zeros_like ( arg ) + np . nan else : return np . nan
Returns meaningless output no matter what the input(s) is.  If no input,
        returns None.  Otherwise, returns an array of NaNs (or a single NaN) of
        the same size as the first input.