[CAY-2555] Use explicit ArcId in GraphChangeHandler methods

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.2.M1
• Component/s: Core Library
• Assignee: Nikita Timofeev
• Reporter: Nikita Timofeev
• Created: 21/Mar/19 12:09
• Updated: 21/Mar/19 13:14
• Resolved: 21/Mar/19 13:14

Description

GraphChangeHandler uses plain Object as arc identifier:

..
void arcCreated(Object nodeId, Object targetNodeId, Object arcId);
void arcDeleted(Object nodeId, Object targetNodeId, Object arcId);
..

We can introduce ArcId object instead that can hold forward and reverse arc names:

public class ArcId {
    private final String forwardArc;
    private final String reverseArc;
    // ...
}

This change should simplify code maintenance and refactoring.