code: public RequestFuture<?> send(WebhookMessage message)
      {
          Checks.notNull(message, "WebhookMessage");
          return execute(message.getBody());
      }
docs: Sends the provided {@link net.dv8tion.jda.webhook.WebhookMessage WebhookMessage}
  to this webhook.
  
  <p>Hint: Use {@link net.dv8tion.jda.webhook.WebhookMessageBuilder WebhookMessageBuilder} to
  create a {@link net.dv8tion.jda.webhook.WebhookMessage WebhookMessage} instance!
  
  @param  message
  The message to send
  
  @throws IllegalArgumentException
  If the provided message is null
  
  @return {@link net.dv8tion.jda.core.requests.RequestFuture RequestFuture} representing the execution task,
  this will be completed once the message was sent.