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: envar.go
    path of file: ./repos/apns2/vendor/gopkg.in/alecthomas/kingpin.v2
    
    the code of the file until where you have to start completion: package kingpin

import (
	"os"
	"regexp"
)

var (
	envVarValuesSeparator = "\r?\n"
	envVarValuesTrimmer   = regexp.MustCompile(envVarValuesSeparator + "$")
	envVarValuesSplitter  = regexp.MustCompile(envVarValuesSeparator)
)

type envarMixin struct {
	envar   string
	noEnvar bool
}

func (e *envarMixin) HasEnvarValue() bool {
	return e.GetEnvar
    
func (e *envarMixin) GetSplitEnvarValue() []string {
	values := make([]string, 0)

	envarValue := e.GetEnvarValue()
	if envarValue == "" {
		return values
	}

	// Split by new line to extract multiple values, if any.
	trimmed := envVarValuesTrimmer.ReplaceAllString(envarValue, "")
	for _, value := range envVarValuesSplitter.Split(trimmed, -1) {
		values = append(values, value)
	}

	return values
}