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: parse.go
    path of file: ./repos/faasd/vendor/github.com/docker/go-connections/nat
    
    the code of the file until where you have to start completion: package nat

import (
	"fmt"
	"strconv"
	"strings"
)

// PartParser parses and validates the specified string (data) using the specified template
// e.g. ip:public:private -> 192.168.0.1:80:8000
// DEPRECATED: do not use, this function may be removed in a future version
func PartParser(template, data string) (map[string]string, error) {
	// ip:public:private
	var (
		templateParts = strings.Split(template, ":")
		parts         = strings.Split(data, ":")
		out           = make(ma
    
func PartParser(template, data string) (map[string]string, error) {
	// ip:public:private
	var (
		templateParts = strings.Split(template, ":")
		parts         = strings.Split(data, ":")
		out           = make(map[string]string, len(templateParts))
	)
	if len(parts) != len(templateParts) {
		return nil, fmt.Errorf("Invalid format to parse. %s should match template %s", data, template)
	}

	for i, t := range templateParts {
		value := ""
		if len(parts) > i {
			value = parts[i]
		}
		out[t] = value
	}
	return out, nil
}