# File lib/rack/utils.rb, line 141
    def build_nested_query(value, prefix = nil)
      case value
      when Array
        value.map { |v|
          build_nested_query(v, "#{prefix}[]")
        }.join("&")
      when Hash
        value.map { |k, v|
          build_nested_query(v, prefix ? "#{prefix}[#{escape(k)}]" : escape(k))
        }.join("&")
      when String
        raise ArgumentError, "value must be a Hash" if prefix.nil?
        "#{prefix}=#{escape(value)}"
      else
        prefix
      end
    end