1. DomName('ReadableStream.cancel')
  2. DocsEditable()
  3. Experimental()
Future cancel(Object reason)

Source 

@DomName('ReadableStream.cancel')
@DocsEditable()
@Experimental() // untriaged
Future cancel(Object reason) => wrap_jso(_blink.BlinkReadableStream.instance.cancel_Callback_1_(unwrap_jso(this), reason));