The CommandEvent() constructor creates a new CommandEvent object.
new CommandEvent(type)
new CommandEvent(type, options)typeA string with the name of the event. It is case-sensitive and browsers set it to command.
options OptionalAn object that, in addition of the properties defined in Event(), can have the following properties:
source OptionalAn HTMLButtonElement representing the button that was interacted with to cause this event. This can be any element but we recommend only using button as a source to avoid surprises.
command OptionalA string containing the command for the controlled element to take. While manually instantiating a CommandEvent it is possible to use any string value, but it is recommended to use one of the built-in names or prefix with two dashes (--) to ensure forward compatibility.
A new CommandEvent object.