You are working on the benavlabs/fastcrud repository. The source code is checked out at /testbed at commit…

You are working on the benavlabs/fastcrud repository. The source code is checked out at /testbed at commit…: a task in SWE-Lego-RL-2699 (Harbor dataset). However, I encounter an issue: when a foreign key is null, the object is still returned but with all fields set to None.