def METHOD_NAME(self):
    # This collection has no mirror_integration, so
    # there is no MirrorUploader for it.
    collection = self._collection()
    assert None == MirrorUploader.for_collection(collection, ExternalIntegrationLink.COVERS)
    # This collection has a properly configured mirror_integration,
    # so it can have an MirrorUploader.
    integration = self._external_integration(
        ExternalIntegration.S3, ExternalIntegration.STORAGE_GOAL,
        username="username", password="password",
        settings={S3UploaderConfiguration.BOOK_COVERS_BUCKET_KEY: "some-covers"}
    )
    integration_link = self._external_integration_link(
        integration=collection._external_integration,
        other_integration=integration,
        purpose=ExternalIntegrationLink.COVERS
    )
    uploader = MirrorUploader.for_collection(collection, ExternalIntegrationLink.COVERS)
    assert isinstance(uploader, MirrorUploader)