balanceExemptions property
BalanceExemptions is an array of BalanceExemption indicating which account balances could change without a corresponding Operation. balanceExemptions should be used sparingly as they may introduce significant complexity for integrators that attempt to reconcile all account balance changes. If your implementation relies on any BalanceExemptions, you MUST implement historical balance lookup (the ability to query an account balance at any BlockIdentifier).
Implementation
final List<BalanceExemption> balanceExemptions;