In this subtitle, if two or more charges, other than one for a minor traffic violation or possession of cannabis under § 5–601 of the Criminal Law Article, arise from the same incident, transaction, or set of facts, they are considered to be a unit. A charge for a minor traffic violation or possession of cannabis under § 5–601 of the Criminal Law Article that arises from the same incident, transaction, or set of facts as a charge in the unit is not a part of the unit. If a person is not entitled to expungement of one charge or conviction in a unit, the person is not entitled to expungement of any other charge or conviction in the unit. The disposition of a charge for a minor traffic violation that arises from the same incident, transaction, or set of facts as a charge in the unit does not affect any right to expungement of a charge or conviction in the unit.