This is a computation object for sagbi bases. It stores a partial sagbi computation for picking up a computation where it left off. An instance of a SAGBIBasis is constructed with the function sagbiBasis and as the output of sagbi.
Every instance of SAGBIBasis is guaranteed to have the following keys:

ambientRing: The polynomial ring that contains the subring instance's generators.

subringGenerators: A onerow matrix, the generators of the subring.

sagbiGenerators: A onerow matrix, the currently computed sagbi generators.

sagbiDegrees: A onerow matrix, the degrees of the sagbi generators.

sagbiDone: A flag that indicates whether the sagbi computation has completed.

stoppingData=>limit: An integer containing the degree Limit for the binomial Spairs that are computed in the sagbi computation.

presentation: An instance of the PresRing type associated with the subring's generators.

pending, stoppingData=>degree: Internal data used for restarting the sagbi computation.