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: warp2.go
    path of file: ./repos/evcc/charger
    
    the code of the file until where you have to start completion: package charger

import (
	"encoding/json"
	"errors"
	"fmt"
	"slices"
	"time"

	"github.com/evcc-io/evcc/api"
	"github.c
    
func (wb *Warp2) meterValues() ([]float64, error) {
	s, err := wb.meterDetailsG()
	if err != nil {
		return nil, err
	}

	var res []float64
	if err := json.Unmarshal([]byte(s), &res); err != nil {
		return nil, err
	}

	if len(res) <= 5 {
		return nil, errors.New("invalid length")
	}

	return res, nil
}