close method
The close() method of the MIDIPort interface makes the access to
the MIDI device connected to this MIDIPort unavailable.
If the port is successfully closed a new MIDIConnectionEvent is queued
to the MIDIPort.statechange_event and MIDIAccess.statechange_event
events, and the MIDIPort.connection property is changed to "closed".
Implementation
external JSPromise<MIDIPort> close();