* - UT on metrics verifying that all plugins of all blocs have their metrics collectors declared
* - fix error msg
* - redirect Registry of metric to the one that handle the listener
- allow duplicate of metrics collector on the same Registry (case of same plugin in 2 blocs listening metrics on the same address)
* - fix change of signature
* - ensure cleaning metrics before starting the test (metrics collectors are global vars .. and re-used by several tests)
* - I think I fixed this test. Ensure correct mn of hits and clean metrics before test.
* - fix typo in error msg - proposed at review
* - fix typo in comment
* - remove ResetMetrics functions
- change a way to test the numeric metrics : get the diff between begin and end of test
* - oops. removing debug logs
* Create test to verify correct listener behavior
* Create Unset function to remove todo items
* Reset address for prometheus listener before restarting
* Add inline documentation for Unset function
* Make shutdownTimeout a constant and change to five seconds
* Revert ForEach behavior in uniq package
