fn deposit(ref self: ContractState, trove_id: u64, yang_asset: AssetBalance) {
    // There is no need to check the yang address is non-zero because the
    // Sentinel does not allow a zero address yang to be added.

    assert(trove_id != 0, 'ABB: Trove ID cannot be 0');
    assert(trove_id <= self.troves_count.read(), 'ABB: Non-existent trove');
    // note that caller does not need to be the trove's owner to deposit
    // @audit Attacker could deposit for any trove to make it the only trove deposited this yang and being redistributed when bad debt happen
    self.deposit_helper(trove_id, get_caller_address(), yang_asset);
}
