grpc_v2.go
func (g GRPCLoggerV2) Errorf(format string, args ...interface{}) {
	g.l.Errorf(format, args...)
}
func (g GRPCLoggerV2) Errorf(format string, args ...interface{}) {
	g.l.Errorf(format, args...)
}
// Errorf calls Logger.Errorf method with provided arguments.