Provide a macroId to uniquely identify multiple instances of a macro across a confluence instance

As a plugin developer I want to persist information related to the instance of the macro.

One solution would be wo write to a hidden parameter, but I can not write back to the parameter map of com.atlassian.confluence.macro.Macro.execute(...)

So the other solution is to use Bandana as suggested

Therefore I need a unique key to feed into bandanas setValue() - method.