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: common.go
    path of file: ./repos/goldfish/vendor/github.com/michaelklishin/rabbit-hole
    
    the code of the file until where you have to start completion: package rabbithole

import "strconv"

// Extra arguments as a map (on queues, bindings, etc)
type Properties map[string]interface{}

// Port used by RabbitMQ or clients
type Port int

func (p *Port) UnmarshalJSON(b []byte) error {
	stringValue := string(b)
	var 
    
func (p *Port) UnmarshalJSON(b []byte) error {
	stringValue := string(b)
	var parsed int64
	var err error
	if stringValue[0] == '"' && stringValue[len(stringValue)-1] == '"' {
		parsed, err = strconv.ParseInt(stringValue[1:len(stringValue)-1], 10, 32)
	} else {
		parsed, err = strconv.ParseInt(stringValue, 10, 32)
	}
	if err == nil {
		*p = Port(int(parsed))
	}
	return err
}