Section 4. Reimbursement for the excise hereby imposed shall be paid by the occupant of such room or rooms to the operator and each operator in this commonwealth shall add to the rent and shall collect from the occupant the full amount of the excise imposed by this chapter, or an amount equal as nearly as possible or practical to the average equivalent thereof; and such excise shall be a debt from the occupant to the operator, when so added to the rent, and shall be recoverable at law in the same manner as other debts.