Generate content in batch ignores selected node types

When generating 50 or more content nodes (and thus running in batch mode) the nodes types selected in the form are ignored and all node types are used. This does not happen when generating 49 or fewer, and only the selected node types are used.

For under 50 nodes the function generateContent has the following:

  /**
   * Method responsible for creating content when
   * the number of elements is less than 50.
   */
  private function generateContent($values) {
    $values['node_types'] = array_filter($values['node_types']);
    ...

However, in the equivalent batch function generateBatchContent there is no array_filter call.

  /**
   * Method responsible for creating content when
   * the number of elements is greater than 50.
   */
  private function generateBatchContent($values) {

It is easy to replicate: Use a site with two or more content types defined. Delete all content, then on the generate form select only 1 content type but generate 100 nodes. View the full contents list and you'll see some of each node type.

I can provide a patch for the missing array_filter. But maybe this needs test coverage too?