code: def ne(self, event_property, value):
          
          c = self.copy()
          c.filters.append(filters.NE(event_property, value))
          return c
docs: A not-equal filter chain.
  
          >>> request_time = EventExpression('request', 'elapsed_ms')
          >>> filtered = request_time.ne('path', '/')
          >>> print(filtered)
          request(elapsed_ms).ne(path, "/")