code: private void validateAutoTimestampField(PropertyMetadata propertyMetadata) {
      Class<?> dataClass = propertyMetadata.getDeclaredType();
      if (Collections.binarySearch(VALID_TIMESTAMP_TYPES, dataClass.getName()) < 0) {
        String messageFormat = "Field %s in class %s must be one of the following types - %s";
        throw new EntityManagerException(String.format(messageFormat,
            propertyMetadata.getField().getName(), entityClass, VALID_TIMESTAMP_TYPES));
      }
    }
docs: Validates the given property metadata to ensure it is valid for an automatic timestamp field.
  
  @param propertyMetadata
  the metadata to validate