code: function(options) {
          // GPX coordinates are always in longlat WGS84
          this.externalProjection = new OpenLayers.Projection("EPSG:4326");
  
          OpenLayers.Format.XML.prototype.initialize.apply(this, [options]);
      }
docs: Constructor: OpenLayers.Format.GPX
  Create a new parser for GPX.
  
  Parameters:
  options - {Object} An optional object whose properties will be set on
  this instance.