logger.FatalIf(err, "Unable to get IP addresses of this host")

	for _, interf := range ifs {
		addrs, err := interf.Addrs()
		if err != nil {
			continue
		}
		if runtime.GOOS == "windows" && interf.Flags&net.FlagUp == 0 {
			continue
		}

		for _, addr := range addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP
			case *net.IPAddr:
				ip = v.IP
			}

			}
		}
	}
}

func TestSameLocalAddrs(t *testing.T) {
	testCases := []struct {
		addr1       string
		addr2       string
		sameAddr    bool
		expectedErr error
	}{
		{"", "", false, errors.New("unable to process empty address")},
		{":9000", ":9000", true, nil},
		{"localhost:9000", ":9000", true, nil},

	}

	addr = tcpAddr
	return addr
}

// Addrs - returns all address information of TCP listeners.
func (listener *httpListener) Addrs() (addrs []net.Addr) {
	for i := range listener.listeners {
		addrs = append(addrs, listener.listeners[i].Addr())
	}

	return addrs
}

// TCPOptions specify customizable TCP optimizations on raw socket
type TCPOptions struct {

	addrs := []*core.Address{ep.GetEndpoint().GetAddress()}
	for _, a := range ep.GetEndpoint().GetAdditionalAddresses() {
		addrs = append(addrs, a.GetAddress())
	}
	result := make([]string, 0, len(addrs))
	for _, addr := range addrs {
		if addr := addr.GetSocketAddress(); addr != nil {
			result = append(result, addr.Address+":"+strconv.Itoa(int(addr.GetPortValue())))
			continue
		}

	if interfaces, err = net.Interfaces(); err != nil {
		return false, fmt.Errorf("failed to get interfaces")
	}

	for _, ief := range interfaces {
		var addrs []net.Addr
		if addrs, err = ief.Addrs(); err != nil {
			return
		}
		for _, addr := range addrs {
			switch v := addr.(type) {
			case *net.IPNet:
				if v.IP.Equal(targetAddr) {
					return true, nil
				}
			}
		}
	}

		}).DialContext
	}

	return func(ctx context.Context, network, addr string) (conn net.Conn, err error) {
		host, port, err := net.SplitHostPort(addr)
		if err != nil {
			return nil, err
		}

		if net.ParseIP(host) != nil {
			// For IP only setups there is no need for DNS lookups.
			return baseDialCtx(ctx, "tcp", addr)
		}

		ips, err := lookupHost(ctx, host)
		if err != nil {
			return nil, err

						if rv.Len() == 0 {
							builder.AddVar(builder, nil)
						} else {
							for i := 0; i < rv.Len(); i++ {
								if i > 0 {
									builder.WriteByte(',')
								}
								builder.AddVar(builder, rv.Index(i).Interface())
							}
						}
					default:
						builder.AddVar(builder, expr.Vars[idx])
					}
				}
			} else {
				builder.AddVar(builder, expr.Vars[idx])
			}

			idx++

		server := NewServer(testCase.addrs).
			UseHandler(testCase.handler)
		if testCase.certFn != nil {
			server = server.UseTLSConfig(&tls.Config{
				PreferServerCipherSuites: true,
				GetCertificate:           testCase.certFn,
			})
		}
		if server == nil {
			t.Fatalf("Case %v: server: expected: <non-nil>, got: <nil>", (i + 1))
		} else if !reflect.DeepEqual(server.Addrs, testCase.addrs) {

func (limit Limit) Build(builder Builder) {
	if limit.Limit != nil && *limit.Limit >= 0 {
		builder.WriteString("LIMIT ")
		builder.AddVar(builder, *limit.Limit)
	}
	if limit.Offset > 0 {
		if limit.Limit != nil && *limit.Limit >= 0 {
			builder.WriteByte(' ')
		}
		builder.WriteString("OFFSET ")
		builder.AddVar(builder, limit.Offset)
	}
}

// MergeClause merge order by clauses
func (limit Limit) MergeClause(clause *Clause) {

            file.delete();
            file.mkdirs();
            file.deleteOnExit();
            fileTransformer.setPath(file.getAbsolutePath());
            crawler.addUrl(url);
            crawler.getCrawlerContext().setMaxAccessCount(maxCount);
            crawler.getCrawlerContext().setNumOfThread(numOfThread);
            crawler.urlFilter.addInclude(url + ".*");