Error message after recent updates (09/2020) Declaration of FeedsCommentProcessor should be compatible with FeedsProcessor

Problem/Motivation

After updating to most recent versions of feeds (7.x-2.0-beta5), getting the following error message when running drush cc all from the CLI:

Declaration of FeedsCommentProcessor::entityValidate($comment) should be compatible with FeedsProcessor::entityValidate($entity, ?FeedsSource $source = NULL) FeedsCommentProcessor.inc:493

This appears to be due to an update in the Feeds Module which added a parameter to the FeedsProcessor class. From the related issue:

The 7.x-2.0-beta5 release of Feeds changed the arguments of the FeedsProcessor::validateEntity() method, by adding a second parameter: FeedsSource $source = NULL

and

This is a relatively minor issue, I think, as it does not break downstream code - just causes this error to appear. It is up to downstream maintainers to update their classes to match the new FeedsProcessor::entityValidate() method signature.

Steps to reproduce

Install current version of Feeds Comment Processor along with Feeds module version 7.x-2.0-beta5.

Proposed resolution

Update the code in FeedsCommentProcessor.inc such that the function declaration accounts for the extra parameter added in the parent class from Feeds. I believe this may be at or near line 55 in FeedsCommentProcessor.inc:

  /**
   * {@inheritdoc}
   */
  protected function entityValidate($comment) {
    if (!$comment->nid) {
      throw new FeedsValidationException(t('Unable to create comment with empty NID.'));
    }

I'm not currently able to create a patch, but may be able to in the near future.