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: flat.go
    path of file: ./repos/infra/internal/cmd/cliopts
    
    the code of the file until where you have to start completion: package cliopts

import (
	"fmt"
	"os"
	"reflect"
	"strings"

	"github.com/iancoleman/strcase"
	"github.com/mitchellh/mapstructure"
	"github.com/mitchellh/reflectwalk"
	"github.com/spf13/pflag"
)

func loadFromEnv(target interface{}, opts Options) error {
	opts.EnvPrefix = st
    
func getParts(raw string) (string, string) {
	if raw == "" {
		return "", ""
	}
	// Environment variables on windows can begin with =
	// http://blogs.msdn.com/b/oldnewthing/archive/2010/05/06/10008132.aspx
	parts := strings.SplitN(raw[1:], "=", 2)
	key := raw[:1] + parts[0]
	if len(parts) == 1 {
		return key, ""
	}
	return key, parts[1]
}