docs: def parse(self, text, layers=None):
          """Parsing passed text to json.
  
          Args:
              text: Text to parse.
              layers (optional): Special fields. Only one string
                  or iterable object (e.g "Data", ("Data", "Fio")).
                  Only these fields will be returned.
  
  
          Returns:
              The parsed text into a json object.
          """
          params = {
              "text": text,
              "key": self.key,
          }
  
          if layers is not None:
              # if it's string
              if isinstance(layers, six.string_types):
                  params["layers"] = layers
  
              # if it's another iterable object
              elif isinstance(layers, collections.Iterable):
                  params["layers"] = ",".join(layers)
  
          req = requests.get(self.NLU_URL, params=params)
          return req.json()