@Override
    public int hashCode() {
        int result = first != null ? first.hashCode() : 0;
        result = 31 * result + operationChangeLogThreshold;
        result = 31 * result + (operationChangeLog != null ? operationChangeLog.hashCode() : 0);
        result = 31 * result + (int) (operationChangeLogSize ^ (operationChangeLogSize >>> 32));
        result = 31 * result + (forceFullSnapshot ? 1 : 0);
        result = 31 * result + (isOperationLogEnabled ? 1 : 0);
        result = 31 * result + eventIndex;
        return result;
    }
Returns the next element in the iteration.

@return the next element in the iteration.
@throws NoSuchElementException iteration has no more elements.
modules/siddhi-core/src/main/java/io/siddhi/core/event/stream/holder/SnapshotableStreamEventQueue.java