Called by the API to provide tenor cutoff information. Use the callback to provide a map of
tenors to boolean values stating whether the tenor is cutoff. The callback can be stored
and called later to update the tenor cutoff state.
subjectInfo - The subject info for the Tenor Dates request.
tenors - The set of tenors to provide cutoffs for, provided earlier.
callback - The callback, which should be called with a map of tenors to their cutoff state.