Content Collection
If you want to retrieve a dummie Content Collection:
/** @var \Blackbird\ContentManager\Model\ResourceModel\ContentType\CollectionFactory $contentCollectionFactory */
$contentCollection = $contentCollectionFactory->create();
or
/** @var \Blackbird\ContentManager\Model\Content $contentModel */
$contentCollection = $contentModel->getCollection();
If you want to retrieve a Content Collection from a specific Content Type:
/** @var \Blackbird\ContentManager\Model\ResourceModel\ContentType\CollectionFactory $contentCollectionFactory */
$contentCollection = $contentCollectionFactory->create()->addContentTypeFilter($contentType);
where $contentType can be string|int|\Blackbird\ContentManager\Model\ResourceModel\Content\ContentType
or
/** @var \Blackbird\ContentManager\Model\ContentType $contentType */
$contentCollection = $contentType->load($contentTypeId)->getContentCollection();
where $contentTypeId is the content type ID. In fact you should call the getContentCollection() on a instantiate and existing content type, not on a empty content type object.