code: public static WebSocketClientHandshaker newHandshaker(
              URI webSocketURL, WebSocketVersion version, String subprotocol,
              boolean allowExtensions, HttpHeaders customHeaders, int maxFramePayloadLength) {
          return newHandshaker(webSocketURL, version, subprotocol, allowExtensions, customHeaders,
                               maxFramePayloadLength, true, false);
      }
docs: Creates a new handshaker.
  
  @param webSocketURL
  URL for web socket communications. e.g "ws://myhost.com/mypath".
  Subsequent web socket frames will be sent to this URL.
  @param version
  Version of web socket specification to use to connect to the server
  @param subprotocol
  Sub protocol request sent to the server. Null if no sub-protocol support is required.
  @param allowExtensions
  Allow extensions to be used in the reserved bits of the web socket frame
  @param customHeaders
  Custom HTTP headers to send during the handshake
  @param maxFramePayloadLength
  Maximum allowable frame payload length. Setting this value to your application's
  requirement may reduce denial of service attacks using long data frames.