<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def quote_by_instruments(cls, client, ids):
 """ create instrument urls, fetch, return results """

        base_url = "https://api.robinhood.com/instruments"
        id_urls = ["{}/{}/".format(base_url, _id) for _id in ids]
        return cls.quotes_by_instrument_urls(client, id_urls)