# File lib/httpclient/util.rb, line 61
    def argument_to_hash(args, *field)
      return nil if args.empty?
      if args.size == 1 and args[0].is_a?(Hash)
        r = args[0].values_at(*field)
        unless r.compact.empty?
          return args[0]
        end
      end
      h = {}
      field.each_with_index do |e, idx|
        h[e] = args[idx]
      end
      h
    end