You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: transport.go
    path of file: ./repos/Xray-core/infra/conf
    
    the code of the file until where you have to start completion: package conf

import (
	"github.com/xtls/xray-core/common/serial"
	"github.com/xtls/xray-core/transport/global"
	"github.com/xtls/xray-core/transport/internet"
)

type TransportConfig struct {
	TCPConfig         *TCPConfig          `json:"tcpSettings"`
	KCPConfig         *KCPConfig          `json:"kcpSettings"`
	WSConfig          *WebSocketConfig    `json:"wsSettings"`
	HTTPConfig        *HTTPConfig         `json:"httpSettings"`
	DSConfig          *DomainSocketConfig `json:"dsSettings"`
	QUICConfig        *QUICConfig         `json:"quicSettings"`
	GRPCConfig        *GRPCConfig         `json:"grpcSettings"`
	GUNConfig         *GRPCConfig         `json:"gunSettings"`
	HTTPUPGRADEConfig *HttpUpgradeConfig  `json:"httpupgradeSettings"`
}

// Build implements Buildable.
func (c *TransportConfig) Build() (*global.Config, error) {
	config := new(global.Config)

	if c.TCPConfig != nil {
		ts, err := c.TCPConfig.Build()
		if err != nil {
			return nil, newError("failed to build TCP config").Base(err).AtError()
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "tcp",
			Settings:     serial.ToTypedMessage(ts),
		})
	}

	if c.KCPConfig != nil {
		ts, err := c.KCPConfig.Build()
		if err != nil {
			return nil, newError("failed to build mKCP config").Base(err).AtError()
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "mkcp",
			Settings:     serial.ToTypedMessage(ts),
		})
	}

	if c.WSConfig != nil {
		ts, err := c.WSConfig.Build()
		if err != nil {
			return nil, newError("failed to build WebSocket config").Base(err)
		}
		config.TransportSettings = 
    
func (c *TransportConfig) Build() (*global.Config, error) {
	config := new(global.Config)

	if c.TCPConfig != nil {
		ts, err := c.TCPConfig.Build()
		if err != nil {
			return nil, newError("failed to build TCP config").Base(err).AtError()
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "tcp",
			Settings:     serial.ToTypedMessage(ts),
		})
	}

	if c.KCPConfig != nil {
		ts, err := c.KCPConfig.Build()
		if err != nil {
			return nil, newError("failed to build mKCP config").Base(err).AtError()
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "mkcp",
			Settings:     serial.ToTypedMessage(ts),
		})
	}

	if c.WSConfig != nil {
		ts, err := c.WSConfig.Build()
		if err != nil {
			return nil, newError("failed to build WebSocket config").Base(err)
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "websocket",
			Settings:     serial.ToTypedMessage(ts),
		})
	}

	if c.HTTPConfig != nil {
		ts, err := c.HTTPConfig.Build()
		if err != nil {
			return nil, newError("Failed to build HTTP config.").Base(err)
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "http",
			Settings:     serial.ToTypedMessage(ts),
		})
	}

	if c.DSConfig != nil {
		ds, err := c.DSConfig.Build()
		if err != nil {
			return nil, newError("Failed to build DomainSocket config.").Base(err)
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "domainsocket",
			Settings:     serial.ToTypedMessage(ds),
		})
	}

	if c.QUICConfig != nil {
		qs, err := c.QUICConfig.Build()
		if err != nil {
			return nil, newError("Failed to build QUIC config.").Base(err)
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "quic",
			Settings:     serial.ToTypedMessage(qs),
		})
	}

	if c.GRPCConfig == nil {
		c.GRPCConfig = c.GUNConfig
	}
	if c.GRPCConfig != nil {
		gs, err := c.GRPCConfig.Build()
		if err != nil {
			return nil, newError("Failed to build gRPC config.").Base(err)
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "grpc",
			Settings:     serial.ToTypedMessage(gs),
		})
	}

	if c.HTTPUPGRADEConfig != nil {
		hs, err := c.HTTPUPGRADEConfig.Build()
		if err != nil {
			return nil, newError("failed to build HttpUpgrade config").Base(err)
		}
		config.TransportSettings = append(config.TransportSettings, &internet.TransportConfig{
			ProtocolName: "httpupgrade",
			Settings:     serial.ToTypedMessage(hs),
		})
	}

	return config, nil
}