code: function (mUnitMappings) {
  			// add custom units, or remove the existing ones if none are given
  			var mExistingUnits = this.getUnitMappings();
  			if (mExistingUnits){
  				mUnitMappings = jQuery.extend({}, mExistingUnits, mUnitMappings);
  			}
  			this.setUnitMappings(mUnitMappings);
  			return this;
  		}
docs: Adds unit mappings.
  Similar to {@link sap.ui.core.Configuration#setUnitMappings} but instead of setting the unit mappings, it will add additional ones.
  @param mUnitMappings {object} unit mappings
  @return {sap.ui.core.Configuration.FormatSettings}
  @see sap.ui.core.Configuration#setUnitMappings