  function selfStake(uint88 amount, uint64 duration) external whenNotPaused {
...
    if (amount == 0) {
      revert AmountMustBeGreaterThanZero();
    }
...}
  function communityStake(address stakee, uint88 amount, uint64 duration) external whenNotPaused {
...
    if (amount == 0) {
      revert AmountMustBeGreaterThanZero();
    }
...
