GObject.Object.prototype.emit

function emit(signal_and_detail: String, ...: Any): Any {
    // Gjs wrapper for g_signal_emit()
}

Emits a signal on the instance.

signal_and_detail: the signal name to emit, in the form signal::detail, or just signal if details are not useful
...: parameters for the signal (which must be values that can be marshalled to C, such as primitives or JS object wrappers)
Returns: the return value from the signal invocation, which depends on the signal accumulator