Returns <code>true</code> if the device has been disposed,
and <code>false</code> otherwise.
<p>
This method gets the dispose state for the device.
When a device has been disposed, it is an error to
invoke any other method using the device.
@return <code>true</code> when the device is disposed and <code>false</code> otherwise
Returns <code>true</code> if the device has been disposed, and <code>false</code> otherwise. <p> This method gets the dispose state for the device. When a device has been disposed, it is an error to invoke any other method using the device.
@return <code>true</code> when the device is disposed and <code>false</code> otherwise