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: checksum.go
    path of file: ./repos/sliver/implant/vendor/gvisor.dev/gvisor/pkg/tcpip/header
    
    the code of the file until where you have to start completion: // Copyright 2018 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file e
    
func PseudoHeaderChecksum(protocol tcpip.TransportProtocolNumber, srcAddr tcpip.Address, dstAddr tcpip.Address, totalLen uint16) uint16 {
	xsum := checksum.Checksum(srcAddr.AsSlice(), 0)
	xsum = checksum.Checksum(dstAddr.AsSlice(), xsum)

	// Add the length portion of the checksum to the pseudo-checksum.
	var tmp [2]byte
	binary.BigEndian.PutUint16(tmp[:], totalLen)
	xsum = checksum.Checksum(tmp[:], xsum)

	return checksum.Checksum([]byte{0, uint8(protocol)}, xsum)
}