Should CompositeFunctionTimer implement mean?

[marschall]

Please describe the feature request. CompositeFunctionTimer currently inherits the default #mean(TimeUnit) implementation from FunctionTimer. Should it implement it and delegate to the first child instead like #count() and #totalTime(TimeUnit)?

Rationale Only one method delegation instead of two. If the first child already implements #mean(TimeUnit) instead of inheriting it even more efficiency gains may be possible.