MC-29411: PHPStan: "Return typehint of method has invalid type " errors

Author: zakdma

app/code/Magento/CatalogSearch/Model/Advanced.php

@@ -359,6 +359,8 @@ protected function getPreparedSearchCriteria($attribute, $value)
         if (is_array($value)) {
             if (isset($value['from']) && isset($value['to'])) {
                 if (!empty($value['from']) || !empty($value['to'])) {
+                    $from = '';
+                    $to = '';
                     if (isset($value['currency'])) {
                         /** @var $currencyModel Currency */
                         $currencyModel = $this->_currencyFactory->create()->load($value['currency']);