Method cancel

api/src/main/java/io/grpc/ClientCall.java:229–229

Prevent any further processing for this ClientCall. No further messages may be sent or will be received. The server is informed of cancellations, but may not stop processing the call. Cancellation is permitted even if previously #halfClosed. Cancelling an already cancel()ed {

(@Nullable String message, @Nullable Throwable cause)

   * @param cause if not {@code null}, will appear as the cause of the CANCELLED status
   */
  public abstract void cancel(@Nullable String message, @Nullable Throwable cause);

  /**
   * Close the call for request message sending. Incoming response messages are unaffected.  This