In Laborers Health & Welfare Trust Fund for N. California v. Advanced Lightweight Concrete Co., 484 U.S. 539, 108 S.Ct. 830, 98 L.Ed.2d 936 (1988), a company that was a party to two multi-employer collective bargaining agreements notified the respective unions well in advance that it would cease contributing to the funds once the agreements expired. When the company failed to make contributions beyond the expiration date set forth in the agreements, trustees of the multi-employer plan brought suit against the company to recover postcontract contributions under section 515 of ERISA. The Supreme Court held in favor of the company on the ground that an employer's liability under section 515 of ERISA is limited to the effective period of the collective bargaining agreement. Id. at 548-49, 108 S.Ct. at 835-36. In Laborers Health & Welfare Fund for N. Cal. v. Advanced Lightweight Concrete Co., 484 U.S. 539, 108 S.Ct. 830, 98 L.Ed.2d 936 (1988), a pension fund sought postcontract contributions under Sec. 1132(g)(2) of ERISA, based upon an employer's failure to maintain the status quo. 484 U.S. at 542, 108 S.Ct. at 832. The Supreme Court noted that the employer's postcontract obligation to contribute was derived, not from ERISA, but from the NLRA. Id. at 545-46, 108 S.Ct. at 833-34. The Supreme Court therefore held that, under Sec. 1132(g)(2) of ERISA, original federal jurisdiction was limited to actions for contractual contributions; contributions owed solely as a result of a noncontractual statutory duty to maintain the status quo properly are sought initially in an action before the NLRB. Id. at 548-49, 108 S.Ct. at 835-36. In Laborers Health & Welfare Trust Fund v. Advanced Lightweight Concrete Co., 484 U.S. 539 (1988), the Supreme Court held that ERISA Sections 502(g)(2) and 515 do not confer subject matter jurisdiction over claims "to determine whether an employer's unilateral decision to refuse to make postcontract contributions constitutes a violation of the National Labor Relations Act." 484 U.S. at 549. According to the Court, Sections 502(g)(2) and 515 confer jurisdiction only over claims for "promised contributions," not over unfair labor practice claims that an employer has refused to bargain in good faith by failing to make postcontract benefit plan contributions before negotiations for a new contract reached an impasse. See Advanced Lightweight, 484 U.S. at 548-49. The decision, therefore, stands only for the unremarkable proposition that the National Labor Relations Board generally has exclusive jurisdiction over unfair labor practice claims. See NLRB v. Katz, 369 U.S. 736, 743 (1962) (holding that employer's failure to honor terms of expired CBA during negotiations on new CBA constitutes unfair labor practice); Advanced Lightweight, 484 U.S. at 543 n.4 ("As a general rule, federal courts do not have jurisdiction over" unfair labor practice claims.) (internal quotation marks omitted); but see id. (noting that federal courts have jurisdiction over unfair labor practice claims that are "collateral" to claims over which there is an independent basis for jurisdiction).