static validatePropertyValue(value, propData) {
      const isMultiple = propData.multiple;
      if (isMultiple && value) {
        return value.map(propValue => validateSingleProperty(propValue, propData));
      }
      return validateSingleProperty(value, propData);
    }
Validates the property's value and returns it if correct
or returns the default value if not.
<b>Note:</b> Only intended for use by UI5Element.js
@public