code: def _query_iedb(request_values, url):
      
      data = urlencode(request_values)
      req = Request(url, data.encode("ascii"))
      response = urlopen(req).read()
      return _parse_iedb_response(response)
docs: Call into IEDB's web API for MHC binding prediction using request dictionary
      with fields:
          - "method"
          - "length"
          - "sequence_text"
          - "allele"
  
      Parse the response into a DataFrame.