Example Lenz's law.
F = (G m M/r2) e,
Note that there is some indication that quantum mechanical considerations in quantum gravity will result in a "quantum hair" coming into play. However, that 1. would constitute a prediction of a theory which does not yet formally exist, and 2. is utterly insignificant for solar-massed black holes, the only types that can be formed today.
See Michelson-Morley experiment.