    # File lib/termtter/command.rb, line 14
        def initialize(args)
          raise ArgumentError, ":name is not given." unless args.has_key?(:name)
          args = args.dup
          args[:exec_proc] ||= args[:exec]
          args[:completion_proc] ||= args[:completion]
          args[:aliases] ||= [args[:alias]].compact

          cfg = {
            :aliases => [],
            :exec_proc => lambda {|arg| },
            :comletion_proc => lambda {|command, arg| [] },
            :author => 'ujihisa',
          }.merge(args) {|k, v1, v2| v2 ? v2 : v1 }

          set cfg
        end