def to_key( key )
      case key
      when :root, 'root'; :root
      when String; key
      when Symbol; key.to_s
      when Module; key.logger_name
      when Object; key.class.logger_name
      end
    end
def to_key( key )
      case key
      when :root, 'root'; :root
      when String; key
      when Symbol; key.to_s
      when Module; key.logger_name
      when Object; key.class.logger_name
      end
    end
call-seq:
    to_key( key )

 Takes the given _key_ and converts it into a form that can be used to
 retrieve a logger from the +Repository+ hash.

 When _key_ is a +String+ or a +Symbol+ it will be returned "as is".
 When _key_ is a +Class+ the class name will be returned. When _key_ is
 an object the name of the object's class will be returned.