docs: function printUsage () {
      log ('This is an example of a basic command-line interface to all exchanges')
      log ('Usage: node', process.argv[1], 'id'.green, 'method'.yellow, '"param1" param2 "param3" param4 ...'.blue)
      log ('Examples:')
      log ('node', process.argv[1], 'okcoinusd fetchOHLCV BTC/USD 15m')
      log ('node', process.argv[1], 'bitfinex fetchBalance')
      log ('node', process.argv[1], 'kraken fetchOrderBook ETH/BTC')
      printSupportedExchanges ()
      log ('Supported options:')
      log ('--verbose         Print verbose output')
      log ('--debug           Print debugging output')
      log ('--cloudscrape     Use https://github.com/codemanki/cloudscraper to bypass Cloudflare')
      log ('--cfscrape        Use https://github.com/Anorov/cloudflare-scrape to bypass Cloudflare (requires python and cfscrape)')
      log ('--poll            Repeat continuously in rate-limited mode')
      log ("--no-send         Print the request but don't actually send it to the exchange (sets verbose and load-markets)")
      log ('--no-load-markets Do not pre-load markets (for debugging)')
      log ('--details         Print detailed fetch responses')
      log ('--no-table        Do not print the fetch response as a table')
      log ('--table           Print the fetch response as a table')
      log ('--iso8601         Print timestamps as ISO8601 datetimes')
      log ('--cors            use CORS proxy for debugging')
  }