# File lib/celluloid/io/dns_resolver.rb, line 35
      def resolve(hostname)
        if host = resolve_hostname(hostname)
          unless ip_address = resolve_host(host)
            fail Resolv::ResolvError, "invalid entry in hosts file: #{host}"
          end
          return ip_address
        end

        query = build_query(hostname)
        @socket.send query.encode, 0, @server.to_s, DNS_PORT
        data, _ = @socket.recvfrom(MAX_PACKET_SIZE)
        response = Resolv::DNS::Message.decode(data)

        addrs = []
        # The answer might include IN::CNAME entries so filters them out
        # to include IN::A & IN::AAAA entries only.
        response.each_answer { |name, ttl, value| addrs << value.address if value.respond_to?(:address) }

        return if addrs.empty?
        return addrs.first if addrs.size == 1
        addrs
      end