code: def _pop_none(self, kwargs):
          
          for key, value in copy(kwargs).items():
              # options with multiple=True return a tuple
              if value is None or value == ():
                  kwargs.pop(key)
              if hasattr(value, 'read'):
                  kwargs[key] = value.read()
docs: Remove default values (anything where the value is None). click is unfortunately bad at the way it
          sends through unspecified defaults.