src/vs/workbench/api/common/extHostDocuments.ts/ExtHostDocuments/getDocumentData
class ExtHostDocuments:	public getDocumentData(resource: vscode.Uri): ExtHostDocumentData | undefined {
		if (!resource) {
			return undefined;
		}
		const data = this._documentsAndEditors.getDocument(resource);
		if (data) {
			return data;
		}
		return undefined;
	}