extensions/ipynb/src/notebookAttachmentCleaner.ts/AttachmentCleaner/checkMetadataHasAttachmentsField
class AttachmentCleaner:	private checkMetadataHasAttachmentsField(metadata: { [key: string]: unknown }): metadata is { readonly attachments: Record<string, unknown> } {
		return !!metadata.attachments && typeof metadata.attachments === 'object';
	}