addCustomUnits(mUnits) {
			const mExistingUnits = Formatting.getCustomUnits();
			if (mExistingUnits){
				mUnits = extend({}, mExistingUnits, mUnits);
			}
			Formatting.setCustomUnits(mUnits);
		}
Adds custom units.

<b>Note:</b> Adding custom units affects all applications running with the current UI5 core instance.

@param {Object<string,module:sap/base/i18n/Formatting.CustomUnit>} mUnits
  A map with the unit code as key and a custom unit definition as value; already existing custom units are
  replaced, new ones are added; see {@link #.getCustomUnits Formatting.getCustomUnits} for an example

@public
@since 1.123