code: @CheckReturnValue
      public GuildManager setSplash(Icon splash)
      {
          Checks.check(splash == null || getGuild().getFeatures().contains("INVITE_SPLASH"), "Cannot set a splash on this guild");
          this.splash = splash;
          set |= SPLASH;
          return this;
      }
docs: Sets the Splash {@link net.dv8tion.jda.core.entities.Icon Icon} of this {@link net.dv8tion.jda.core.entities.Guild Guild}.
  
  @param  splash
  The new splash for this {@link net.dv8tion.jda.core.entities.Guild Guild}
  or {@code null} to reset
  
  @throws IllegalArgumentException
  If the guild's {@link net.dv8tion.jda.core.entities.Guild#getFeatures() features} does not include {@code INVITE_SPLASH}
  
  @return GuildManager for chaining convenience