A condition contained in debentures, or in a deed for securing debentures, is not invalid by reason only that the debentures are made—
irredeemable, or
redeemable only—
on the happening of a contingency (however remote), or
on the expiration of a period (however long),
any rule of equity to the contrary notwithstanding.
Subsection (1) applies to debentures whenever issued and to deeds whenever executed.