code: public ApplicationAction setDescription(final String description)
      {
          if (description != null && description.length() > 400)
              throw new IllegalArgumentException("The description must not be more than 400 characters!");
  
          this.description = description;
          return this;
      }
docs: Sets the <b><u>description</u></b> for the new {@link net.dv8tion.jda.client.entities.Application Application}.
  Passing {@code null} or an empty {@link String} will reset the description.
  
  <p>A description <b>must not</b> be than 400 characters long!
  
  @param  description
  The description for new {@link net.dv8tion.jda.client.entities.Application Application}
  
  @throws IllegalArgumentException
  If the provided description is more than 400 characters long
  
  @return The current ApplicationAction for chaining