# File lib/core/facets/enumerable/per.rb, line 18
  def per(enum_method=nil, *enum_args)
    if enum_method
      Permeator.new(self, enum_method, *enum_args)
      #Functor.new do |op, *args|
      #  __send__(enum_method, *enum_args){ |x| x.__send__(op, *args) } #, &blk) }
      #end
    else
      @__per__ ||= Functor.new do |enum_method, *enum_args|
        Permeator.new(self, enum_method, *enum_args)
        #Functor.new do |op, *args|
        #  __send__(enum_method, *enum_args){ |x| x.__send__(op, *args) } #, &blk) }
        #end
      end
    end
  end