The change stream watch commands offered by the mongo jstest shell take an `options` argument for the change stream's options, but the internal function that passes the options to the change stream aggregate command modifies this `options` object in-place, deleting keys from it. For example, when passing the same `options` object to 2 separate change stream watch commands, the first call can silently remove options from the original object, so that the second call will effectively use different options:

const options =

{showExpandedEvents: true}

;

// Change stream is opened with

{showExpandedEvents: true}

, but call
// silently drops 'showExpandedEvents' flag from 'options'.
coll.watch([], options);

// Change stream is opened with only {}!
coll.watch([], options);

This change fixes that by cloning the input options, so that the original options remain unmodified throughout multiple calls to watch.