code: public static CreateFollowRequest checkRequest(
  			final FormItemList formItemList, final CreateRequest createRequest,
  			final CreateFollowResponse createFollowResponse) {
  		final Node user = checkUserIdentifier(formItemList,
  				createFollowResponse);
  		if (user != null) {
  			final Node followed = checkFollowedIdentifier(formItemList,
  					createFollowResponse);
  			if (followed != null) {
  				return new CreateFollowRequest(createRequest.getType(), user,
  						followed);
  			}
  		}
  
  		return null;
  	}
docs: check a create follow edge request for validity concerning NSSP
  
  @param formItemList
  form item list extracted
  @param createRequest
  basic create request object
  @param createFollowResponse
  create follow edge response object
  @return create follow edge request object<br>
  <b>null</b> if the create follow edge request is invalid