ยง 1004. When joinder unnecessary. Except where otherwise prescribed by order of the court, an executor, administrator, guardian of the property of an infant, committee of the property of a judicially declared incompetent, conservator of the property of a conservatee, trustee of an express trust, insured person who has executed to his insurer either a loan or subrogation receipt, trust agreement, or other similar agreement, or person with whom or in whose name a contract has been made for the benefit of another, may sue or be sued without joining with him the person for or against whose interest the action is brought.