Validated  object to suppress error message.

## Ready State: Yes (Review needed)
#### JIRA Reference: https://imagex.atlassian.net/browse/LDC-663

This is a fix for Linux.com - Validates the $entity object to suppress the error message showing invalid property field_imagex_aggregator. However, this may not be entirely appropriate, if for some reason, this property should exist in this context, but is missing.