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: envconfig.go
    path of file: ./repos/marketstore/contrib/alpacabkfeeder/configs
    
    the code of the file until where you have to start completion: package configs

import (
	"os"
	"time"
)

// APItoken, UpdateTime, and Basic Auth of stocksJsonURL settings can be overridden by environment variables
// to flexibly re-run processes that are performed only at marketstore start-up/certain times of the day
// and not to write security-related configs directly in the configuration file.

// envOverride updates some configs by environment variables.
func envOverride(config *DefaultConfig) (*DefaultConfig, error) {
	// override SymbolsUpdateTime
	symbolsUpdateTime := os.Getenv("ALPACA_BROKER_FEEDER_SYMBOLS_UPDATE_TIME")
	if symbolsUpdateTim
    
func envOverride(config *DefaultConfig) (*DefaultConfig, error) {
	// override SymbolsUpdateTime
	symbolsUpdateTime := os.Getenv("ALPACA_BROKER_FEEDER_SYMBOLS_UPDATE_TIME")
	if symbolsUpdateTime != "" {
		t, err := time.Parse(ctLayout, symbolsUpdateTime)
		if err != nil {
			return nil, err
		}
		config.SymbolsUpdateTime = t
	}

	// override UpdateTime
	updateTime := os.Getenv("ALPACA_BROKER_FEEDER_UPDATE_TIME")
	if updateTime != "" {
		t, err := time.Parse(ctLayout, updateTime)
		if err != nil {
			return nil, err
		}
		config.UpdateTime = t
	}

	// override API Key ID / API Secret Key
	apiKeyID := os.Getenv("ALPACA_BROKER_FEEDER_API_KEY_ID")
	if apiKeyID != "" {
		config.APIKeyID = apiKeyID
	}

	apiSecretKey := os.Getenv("ALPACA_BROKER_FEEDER_API_SECRET_KEY")
	if apiSecretKey != "" {
		config.APISecretKey = apiSecretKey
	}

	// override the basic Auth of Stocks Json URL and basic auth
	// override the basic Auth of Stocks Json URL
	stocksJSONURL := os.Getenv("ALPACA_BROKER_FEEDER_STOCKS_JSON_URL")
	if stocksJSONURL != "" {
		config.StocksJSONURL = stocksJSONURL
	}
	stocksJSONBasicAuth := os.Getenv("ALPACA_BROKER_FEEDER_STOCKS_JSON_BASIC_AUTH")
	if stocksJSONBasicAuth != "" {
		config.StocksJSONBasicAuth = stocksJSONBasicAuth
	}

	return config, nil
}