Neb. Rev. Stat. § 76-828

Except as expressly provided in sections 76-825 to 76-894 , provisions of sections 76-825 to 76-894 may not be varied by agreement, and rights conferred by sections 76-825 to 76-894 may not be waived. A declarant may not act under a power of attorney, or use any other device, to evade the limitations or prohibitions of sections 76-825 to 76-894 or the declaration.