code: function(sPropertyName) {
  			if (!sPropertyName) {
  				return;
  			}
  
  			var oSorter = this._containsSorter(sPropertyName);
  			if (oSorter) {
  				this._removeFromArray(this._aSortCondition, oSorter.index);
  			}
  		}
docs: Removes the order by expression for the given property name from the list
  of order by expression. If no order by expression with this property name
  exists the method does nothing.
  
  @param {string}
  sPropertyName The name of the property to be removed from the
  condition
  @public
  @function
  @name sap.ui.model.analytics.odata4analytics.SortExpression#removeSorter