'if implprefix is given implementation functions
will be recognized if their name matches the implprefix.'

def __init__(self, project_name, implprefix=None):

    self.project_name = project_name
    self._name2plugin = {}
    self._plugin2hookcallers = {}
    self._plugin_distinfo = []
    self.trace = _TagTracer().get('pluginmanage')
    self.hook = _HookRelay(self.trace.root.get('hook'))
    self._implprefix = implprefix
    self._inner_hookexec = (lambda hook, methods, kwargs: _MultiCall(methods, kwargs, hook.spec_opts).execute())
