I am trying to trigger a MUI Select using Cypress but I cannot get it to work.

I have read the MUI SelectInput source and it is clear they are triggering on "mousedown" event. I have profiled a click and seen that this is true. However, calling `cy.find(input).trigger('mousedown', { force: true })` doesn't trigger the popup, nor does `cy.find('label').trigger('mousedown', { force: true })`, nor does grabbing any of the containing `div` elements and triggering mousedown on them.

If I go to the MUI example page:
<https://material-ui.com/components/selects/>
and I inspect the DOM there and look at the elements, none of them have an onmousedown handler, and grabbing them as globals and calling `temp<n>.dispatchEvent(new MouseEvent('mousedown'))` doesn't trigger the popup to open. So I cannot figure out where the mousedown handler is being hooked.

What am I missing?

Thanks in advance.