getTexts(mPropertyBag) {
			return _getWriteConnectors()
			.then(_executeActionByName.bind(undefined, "translation.getTexts", mPropertyBag));
		}
Gets the translatable texts for the given source & target language for the given application

@param {object} mPropertyBag - Property bag
@param {sap.ui.fl.Layer} mPropertyBag.layer - Layer
@param {string} mPropertyBag.sourceLanguage - Source language for which the request should be made
@param {string} mPropertyBag.targetLanguage - Target language for which the request should be made
@param {string} mPropertyBag.reference - Flexibility reference
@returns {Promise} Resolving after the languages are retrieved;
rejects if an error occurs