Returns the base inferred from expected_states.
The intent is to allow users to discriminate states higher than 0/1.
DiscriminationFilter infers the basis from the expected states to allow users to discriminate states outside of the computational sub-space. For example, if the discriminated states are 00, 01, 02, 10, 11, ..., 22 the basis will be 3.
With this implementation the basis can be at most 10.
the base inferred from the expected states
- Return type
QiskitError -- if there is an invalid input in the expected states