each_pair

# File actionpack/lib/action_dispatch/http/query_parser.rb, line 29
    def self.each_pair(s, separator = nil)
      return enum_for(:each_pair, s, separator) unless block_given?

      s ||= ""

      splitter =
        if separator
          COMMON_SEP[separator] || /[#{separator}] */
        else
          DEFAULT_SEP
        end

      s.split(splitter).each do |part|
        next if part.empty?

        k, v = part.split("=", 2)

        k = URI.decode_www_form_component(k)
        v &&= URI.decode_www_form_component(v)

        yield k, v
      end

      nil
    end