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: estimator.go
    path of file: ./repos/evcc/core/soc
    
    the code of the file until where you have to start completion: package soc

import (
	"errors"
	"time"

	"github.com/evcc-io/evcc/api"
	"github.com/evcc-io/evcc/util"
)

const ChargeEfficiency = 0.9 // assume charge 90% efficiency

// Estimator provides vehicle soc an
    
func NewEstimator(log *util.Logger, charger api.Charger, vehicle api.Vehicle, estimate bool) *Estimator {
	s := &Estimator{
		log:      log,
		charger:  charger,
		vehicle:  vehicle,
		estimate: estimate,
	}

	s.Reset()

	return s
}