Text Telephony hierarchy
========================

Service		org.ofono
Interface	org.ofono.TextTelephony
Object path	[variable prefix]/{modem0,modem1,...}

Methods		dict GetProperties()

			Returns all Text Telephony properties. See the
			properties section for available properties.

			Possible Errors: [service].Error.InProgress
					 [service].Error.Failed

		void SetProperty(string name, variant value)

			Changes the value of the specified property. Only
			properties that are listed as read-write are
			changeable. On success a PropertyChanged signal
			will be emitted.

			Possible Errors: [service].Error.InvalidArguments
					 [service].Error.InProgress
					 [service].Error.Failed

Signals		PropertyChanged(string property, variant value)

			This signal indicates a changed value of the given
			property.

Properties	boolean	Enabled [readwrite]

			This property will enable or disable the text
			telephony feature in the modem.

			Text telephony (TTY), also known as Cellular Text Modem
			(CTM), is a feature present in some modems that allow
			them to be used by hearing impaired people.