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: pconn.go
    path of file: ./repos/nps/lib/pmux
    
    the code of the file until where you have to start completion: package pmux

import (
	"net"
	"time"
)

type PortConn struct {
	Conn     net.Conn
	rs       []byte
	readMore bool
	start    int
}

func newPortConn(conn n
    
func (pConn *PortConn) Read(b []byte) (n int, err error) {
	if len(b) < len(pConn.rs)-pConn.start {
		defer func() {
			pConn.start = pConn.start + len(b)
		}()
		return copy(b, pConn.rs), nil
	}
	if pConn.start < len(pConn.rs) {
		defer func() {
			pConn.start = len(pConn.rs)
		}()
		n = copy(b, pConn.rs[pConn.start:])
		if !pConn.readMore {
			return
		}
	}
	var n2 = 0
	n2, err = pConn.Conn.Read(b[n:])
	n = n + n2
	return
}