Fix undefined reference

openfold/utils/chunk_utils.py

@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from functools import partial
 import logging
 import math
 from typing import Tuple, List, Callable, Any, Dict, Sequence, Optional