public boolean followUser(String followingUser, String userToFollow, String id){
		User userFound= _users.get(userToFollow);
		if ((userFound != null) && (userFound.checkIfCanAddFollowingUser(followingUser, id)) && (_users.get(followingUser).checkIfCanFollowUser(userToFollow, id))){
			userFound.addFollowingUser(followingUser, id);
			_users.get(followingUser).followUser(userToFollow, id);
			return true;
		}
		return false;
	}