Emit DTMF tones (telephony-only). Raises UnsupportedCapabilityError
when the active adapter does not advertise capabilities.dtmf. The
adapter's sendDtmf() is invoked directly — adapters that claim the
capability without implementing the method get a loud failure from the
base-class default rather than a silent PCM fallback.
Emit DTMF tones (telephony-only). Raises UnsupportedCapabilityError when the active adapter does not advertise
capabilities.dtmf. The adapter'ssendDtmf()is invoked directly — adapters that claim the capability without implementing the method get a loud failure from the base-class default rather than a silent PCM fallback.