code: function (record, index) {
  		var code = this.options.codeField ? L.Util.getFieldValue(record, this.options.codeField) : index;
  
  		this._lookupIndex = this._lookupIndex || L.GeometryUtils.indexFeatureCollection(this.options.locationLookup, this.options.locationIndexField || this.options.codeField);
  
  		var geoJSON = this._lookupIndex[code];
  		var location = null;
  
  		if (!geoJSON && code.indexOf('0') === 0) {
  			geoJSON = this._lookupIndex[code.substring(1)];
  		}
  
  		if (geoJSON) {
  			var me = this;
  			var recordToLayer = function (location, record) {
  				return me.recordToLayer(location, record);
  			};
  
  			location = L.GeometryUtils.getGeoJSONLocation(geoJSON, record, this.options.locationTextField, recordToLayer);
  		}
  
  		return location;
  	}
docs: /*
  Each record contains a field with a custom code - Use a custom lookup to find an associated GeoJSON geometry