# File lib/uri_template/rfc6570.rb, line 55
    def def?( value )
      case( value )
      when nil  then
        false
      when Hash then
        value.any?{|_, v| !v.nil? }
      when Array then
        if value.none?
          false
        elsif value[0].kind_of?(Array)
          value.any?{|_,v| !v.nil? }
        else
          value.any?{|v| !v.nil? }
        end
      else
        true
      end
    end