code: def context_complete(self, ctxt):
          
          # Fresh start
          self.complete = False
          self.missing_data = []
          for k, v in six.iteritems(ctxt):
              if v is None or v == '':
                  if k not in self.missing_data:
                      self.missing_data.append(k)
  
          if self.missing_data:
              self.complete = False
              log('Missing required data: %s' % ' '.join(self.missing_data),
                  level=INFO)
          else:
              self.complete = True
          return self.complete
docs: Check for missing data for the required context data.
          Set self.missing_data if it exists and return False.
          Set self.complete if no missing data and return True.