The type of the cached value.
The return type of the callback function.
The collection of documents being processed.
The window operator input containing metadata such as the field name and document number.
A callback function that computes and returns the cached value for the field.
A callback function that processes the cached value and returns the result.
The result of the fn callback function.
A utility function that manages memoization for window operators. It caches intermediate results for a given collection and field, and ensures proper cleanup after processing.