increment method Null safety

void increment(
  1. String key,
  2. num amount
)

Atomically increments the value of the given key with amount.

Implementation

void increment(String key, num amount) {
  if (isNullOrEmpty(key)) {
    throw ArgumentError.notNull('key');
  }
  _LCIncrementOperation op = new _LCIncrementOperation(amount);
  _applyOperation(key, op);
}