code: function (mUnits) {
  			// add custom units, or remove the existing ones if none are given
  			var mExistingUnits = this.getCustomUnits();
  			if (mExistingUnits){
  				mUnits = jQuery.extend({}, mExistingUnits, mUnits);
  			}
  			this.setCustomUnits(mUnits);
  			return this;
  		}
docs: Adds custom units.
  Similar to {@link sap.ui.core.Configuration#setCustomUnits} but instead of setting the custom units, it will add additional ones.
  @param mUnits {object} custom unit object which replaces the current custom unit definition. Call with <code>null</code> to delete custom units.
  @return {sap.ui.core.Configuration.FormatSettings}
  @see sap.ui.core.Configuration#setCustomUnits