code: def field(self, type, field, default=None):
          '''convenient function for returning an arbitrary MAVLink
             field with a default'''
          if not type in self.messages:
              return default
          return getattr(self.messages[type], field, defaultf field(self, type, field, default=None):
          '''convenient function for returning an arbitrary MAVLink
             field with a default'''
          if not type in self.messages:
              return default
          return getattr(self.messages[type], field, default)
docs: convenient function for returning an arbitrary MAVLink
             field with a default