code: def _proxy(self):
          
          if self._context is None:
              self._context = NumberContext(
                  self._version,
                  destination_number=self._solution['destination_number'],
              )
          return self._context
docs: Generate an instance context for the instance, the context is capable of
          performing various actions.  All instance actions are proxied to the context
  
          :returns: NumberContext for this NumberInstance
          :rtype: twilio.rest.pricing.v2.voice.number.NumberContext