code: private AgentClass validateRoomAgentClass(ApiRoom agent) {
  	    AgentClass roomAgentClass = context
  	            .getRoomAgentClass(agent.getClass());
  	    if(roomAgentClass == null)
  	        throw new IllegalStateException("You mus annotate class " + agent.getClass()
  	                + " with @" + RoomAgent.class.getSimpleName());
  	    return roomAgentClass;
  	}
docs: Validate room agent class to check whether room agent be annotated with {@code RoomAgent}
  annotation or not
  
  @param agent room agent object
  @return structure of room agent class
  @throws IllegalStateException when agent class be not annotated with {@code RoomAgent}