on 'op' callback firing multiple times per each submitOp

Hi I have the following code:

shareDoc.on('op', (ops, source) => {
    for (let op of ops) {
        this._dispatchOperation(op);
    }
});

The _dispatchOperation method gets called 4 times for each submitOp with the same ops object and source=true.

Is this by design or is it a bug?

In my case it is not what I want, therefore I modified the code as follows.

this._lastOps = null;
shareDoc.on('op', (ops, source) => {
    if (lodash.isEqual(ops, this._lastOps)) return;
    this._lastOps = ops;
    for (let op of ops) {
        this._dispatchOperation(op);
    }
});

Is this ok or the three op notifications that I am ignoring may be important?

No files or tests are named; start by tracing the shareDoc 'op' listener and submitOp path to reproduce the four notifications and inspect why source=true is repeated. Done means establishing whether the repeated callbacks are by design or a bug, and determining whether the ignored notifications carry distinct operations.