doValidateType example

$this->handlingPlaceholder = $rightSide;
                try {
                    $this->merge($leftSide, $rightPlaceholder);
                } finally {
                    $this->handlingPlaceholder = null;
                }
            }

            return $rightSide;
        }

        $this->doValidateType($leftSide);
        $this->doValidateType($rightSide);

        return $this->mergeValues($leftSide, $rightSide);
    }

    final public function normalize(mixed $value): mixed
    {
        $value = $this->preNormalize($value);

        // run custom normalization closures         foreach ($this->normalizationClosures as $closure) {