Indexing step not working properly when "use_checkpoints" is turned on

[yuvalyaron]

When the indexing step runs with checkpoints enabled - i.e., with the setting in this config json:

"use_checkpoints": true,

no vectors will be created in the index.

This issue occurs because some methods wrapped with a checkpoint cache decorator modify their input arguments. When the method's result is cached, the method doesn't execute again, leaving the input arguments unmodified. This creates a bug, as the calling code expects those arguments to be updated.