code: @CheckReturnValue
      public RoleData newRole()
      {
          final RoleData role = new RoleData(roles.size());
          this.roles.add(role);
          return role;
      }
docs: Creates and add a new {@link net.dv8tion.jda.core.requests.restaction.GuildAction.RoleData RoleData} object
  representing a Role for the resulting Guild.
  
  <p>This can be used in {@link GuildAction.ChannelData#addPermissionOverride(GuildAction.RoleData, long, long) ChannelData.addPermissionOverride(...)}.
  <br>You may change any properties of this {@link net.dv8tion.jda.core.requests.restaction.GuildAction.RoleData RoleData} instance!
  
  @return RoleData for the new Role