wol-soft/php-json-schema-model-generator

/**
 * Get additional properties
 *
 * @return {% if validationProperty %}{% if viewHelper.getTypeHintAnnotation(validationProperty, true) %}{{ viewHelper.getTypeHintAnnotation(validationProperty, true) }}{% endif %}{% else %}array{% endif %}
 */
public function getAdditionalProperties(): array
{
    return $this->_additionalProperties;
}