write(mPropertyBag) {
			mPropertyBag.method = "POST";
			return _doWrite(mPropertyBag);
		}
Write flex data into LRep back end; This method is called with a list of entities like changes, variants,
control variants, variant changes and variant management changes.

@param {object} mPropertyBag Property bag
@param {object[]} mPropertyBag.flexObjects Objects to be written (i.e. change definitions, variant definitions etc.)
@param {string} mPropertyBag.url Configured url for the connector
@param {string} [mPropertyBag.transport] The transport ID
@param {boolean} [mPropertyBag.isLegacyVariant] Whether the new flex data has file type .variant or not
@returns {Promise} Promise resolves as soon as the writing was completed