# File lib/thor/util.rb, line 133
      def find_class_and_command_by_namespace(namespace, fallback = true)
        if namespace.include?(?:) # look for a namespaced command
          pieces  = namespace.split(":")
          command = pieces.pop
          klass   = Thor::Util.find_by_namespace(pieces.join(":"))
        end
        unless klass # look for a Thor::Group with the right name
          klass, command = Thor::Util.find_by_namespace(namespace), nil
        end
        if !klass && fallback # try a command in the default namespace
          command = namespace
          klass   = Thor::Util.find_by_namespace('')
        end
        return klass, command
      end