code: def _check_required_parameters(
              self,
              required_parameters,
              parameters
      ):
          
          self.log([u"Checking required parameters '%s'", required_parameters])
          self.log(u"Checking input parameters are not empty")
          if (parameters is None) or (len(parameters) == 0):
              self._failed(u"No parameters supplied.")
              return
          self.log(u"Checking no required parameter is missing")
          for req_param in required_parameters:
              if req_param not in parameters:
                  self._failed(u"Required parameter '%s' not set." % req_param)
                  return
          self.log(u"Checking all parameter values are allowed")
          self._check_allowed_values(parameters)
          self.log(u"Checking all implied parameters are present")
          self._check_implied_parameters(parameters)
          return self.result
docs: Check whether the given parameter dictionary contains
          all the required paramenters.
          Log messages into ``self.result``.
  
          :param list required_parameters: required parameters
          :param dict parameters: parameters specified by the user