Tests for issues #3931 and #3932
fix for issues #3931 and #3932
Use hashCode and class name to uniquely identify the interceptor
Update the map interceptor documentation to mention that the hashCode() method ca be used to prevent duplicatation of map interceptors
Fix documentation to be on one line. Remove unnecessary comments from test
Mention that adding equals is a good idea
Merge pull request #3994 from dirkvanrensburg/fixinterceptor

Fix for issues #3931 and #3932