Lookup function to identify crosstalkSource entries.
This should return an empty list under most circumstances. Only
when inter-chip crosstalk has been identified should this be
populated.
Parameters
----------
datasetType : `str`
Dataset to lookup.
registry : `lsst.daf.butler.Registry`
Butler registry to query.
quantumDataId : `lsst.daf.butler.ExpandedDataCoordinate`
Data id to transform to identify crosstalkSources. The
``detector`` entry will be stripped.
collections : `lsst.daf.butler.CollectionSearch`
Collections to search through.
Returns
-------
results : `list` [`lsst.daf.butler.DatasetRef`]
List of datasets that match the query that will be used as
crosstalkSources.
Definition at line 61 of file isrTask.py.