Implement a common editor class for implementing the list for relationships between non-functional and functional requirements
At present the design of the non-functional requirements (e.g., timing, signal and mode) is such that I have to implement a list in each of the non-functional requirement explicitly but now the it is required to have a common editor class that enables the implementation of the list that implements the relationship between non-functional and functional requirement
(from redmine: issue id 3226, created on 2017-12-09)