Is there an existing issue for this?

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Describe the bug

The next event handler is not called if the previous event handler removes itself.

Expected Behavior

All registered event handlers have to be called.

Steps To Reproduce

const connection = new HubConnectionBuilder();

...

function emitter1() {
    connection.off(eventName, emitter1);
    console.log('emitter1');
}

function emitter2() {
    console.log('emitter2');
}

connection.on(eventName, emitter1);
connection.on(eventName, emitter2);

When the first event comes in then only emitter1 is called, but not emitter2.