docs: def unwrap(self, value):
          """
          A helper method for unwrapping the loaderplugin fragment out of
          the provided value (typically a modname) and return it.
  
          Note that the filter chaining is very implementation specific to
          each and every loader plugin and their specific toolchain, so
          this default implementation is not going to attempt to consume
          everything in one go.
  
          Another note: if this is to be subclassed and if the return
          value does not actually remove the loaderplugin fragment, issues
          like default implmenetation of ``modname_source_to_target`` in
          this class to recurse forever.
          """
  
          globs = value.split('!', 1)
          if globs[0].split('?', 1)[0] == self.name:
              return globs[-1]
          else:
              return value