code: private static Node checkFollowedIdentifier(
  			final HttpServletRequest request,
  			final DeleteFollowResponse response) {
  		final String followedId = request
  				.getParameter(ProtocolConstants.Parameters.Delete.Follow.FOLLOWED_IDENTIFIER);
  		if (followedId != null) {
  			final Node followed = NeoUtils.getUserByIdentifier(followedId);
  			if (followed != null) {
  				return followed;
  			}
  			response.followedIdentifierInvalid(followedId);
  		} else {
  			response.followedIdentifierMissing();
  		}
  
  		return null;
  	}
docs: check if the request contains a valid followed identifier
  
  @param request
  Tomcat servlet request
  @param response
  response object
  @return user node with the identifier passed<br>
  <b>null</b> if the identifier is invalid