code: def fetch(cls, client, _id, symbol):
          
          url = "https://api.robinhood.com/options/chains/"
          params = {
              "equity_instrument_ids": _id,
              "state": "active",
              "tradability": "tradable"
          }
          data = client.get(url, params=params)
  
          def filter_func(x):
              return x["symbol"] == symbol
          results = list(filter(filter_func, data["results"]))
          return results[0]
docs: fetch option chain for instrument