code: func (b *Bittrex) GetMarketSummaries() (marketSummaries []MarketSummary, err error) {
  	r, err := b.client.do("GET", "public/getmarketsummaries", "", false)
  	if err != nil {
  		return
  	}
  	var response jsonResponse
  	if err = json.Unmarshal(r, &response); err != nil {
  		return
  	}
  	if err = handleErr(response); err != nil {
  		return
  	}
  	err = json.Unmarshal(response.Result, &marketSummaries)
  	return
  }
docs: // GetMarketSummaries is used to get the last 24 hour summary of all active exchanges