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: entry.go
    path of file: ./repos/tegola/vendor/github.com/aws/aws-lambda-go/lambda
    
    the code of the file until where you have to start completion: // Copyright 2017 Amazon.com, Inc. or 
    
func start(handler *handlerOptions) {
	var keys []string
	for _, start := range startFunctions {
		config := os.Getenv(start.env)
		if config != "" {
			// in normal operation, the start function never returns
			// if it does, exit!, this triggers a restart of the lambda function
			err := start.f(config, handler)
			logFatalf("%v", err)
		}
		keys = append(keys, start.env)
	}
	logFatalf("expected AWS Lambda environment variables %s are not defined", keys)

}