Data selection interface. Callable object that indicates the data to be returned to the user.
Examples
>>> interface.select('/projects/myproj/subjects').get()
>>> interface.select('xnat:subjectData', ['xnat:subjectData/PROJECT', 'xnat:subjectData/SUBJECT_ID']
).where([('xnat:subjectData/SUBJECT_ID', 'LIKE', '*'), 'AND'])