Section 15-104 - Supplemental principles of law(a) In any case not provided for in this chapter, the rules of law and equity, including the law merchant, shall govern.(b) No obligation of a partner to a partnership, or to a partner of a partnership, arising under a partnership agreement or a separate agreement or writing, and no note, instruction or other writing evidencing any such obligation of a partner, shall be subject to the defense of usury, and no partner shall interpose the defense of usury with respect to any such obligation in any action. If an obligation to pay interest arises under this chapter and the rate is not specified, the rate is that specified in § 2301 of this title.(c) Sections 9-406 and 9-408 of this title do not apply to any interest in a domestic partnership, including all rights, powers and interests arising under a partnership agreement or this chapter. This provision prevails over §§ 9-406 and 9-408 of this title. 72 Del. Laws, c. 151, § 1; 72 Del. Laws, c. 390, § 4; 73 Del. Laws, c. 223, §1; 78 Del. Laws, c. 271, § 1.;