handlers.go
func (f ErrorHandlerFunc) Handle(ctx context.Context, call *InboundCall) {
	if err := f(ctx, call); err != nil {
		if GetSystemErrorCode(err) == ErrCodeUnexpected {
			call.log.WithFields(f.getLogFields()...).WithFields(ErrField(err)).Error("Unexpected handler error")
		}
		call.Response().SendSystemError(err)
	}
}
func (f ErrorHandlerFunc) Handle(ctx context.Context, call *InboundCall) {
	if err := f(ctx, call); err != nil {
		if GetSystemErrorCode(err) == ErrCodeUnexpected {
			call.log.WithFields(f.getLogFields()...).WithFields(ErrField(err)).Error("Unexpected handler error")
		}
		call.Response().SendSystemError(err)
	}
}
// Handle calls f(ctx, call)