code: function(url) {
              if (!url) {
                  throw new ArgumentError(
                      Logger.logMessage(Logger.LEVEL_SEVERE, "DBaseFile", "constructor", "missingUrl"));
              }
  
              // Internal use only. Intentionally not documented.
              this._url = url;
  
              // Internal use only. Intentionally not documented.
              this._completionCallback = null;
  
              // Internal use only. Intentionally not documented.
              this._params = null;
          }
docs: Constructs an object for a projection descriptor file at a specified URL.
  Applications typically do not call this constructor.
  It is called by {@link Shapefile} to read the projection descriptor.
  @alias PrjFile
  @constructor
  @classdesc Parses a projection descriptor file.
  @param {String} url The location of the dBase file.
  @throws {ArgumentError} If the specified URL is null or undefined.