code: public WebhookMessageBuilder resetFiles()
      {
          for (int i = 0; i < MAX_FILES; i++)
              files[i] = null;
          fileIndex = 0;
          return this;
      }
docs: Removes all added resources.
  The {@link #getFileAmount()} will report {@code 0} after this happened, however the allocated array will remain.
  
  @return The current WebhookMessageBuilder for chaining convenience