code: function(url) {
              if (!url) {
                  throw new ArgumentError(
                      Logger.logMessage(Logger.LEVEL_SEVERE, "DBaseFile", "constructor", "missingUrl"));
              }
  
              this.url = url;
  
              // Internal use only. Intentionally not documented.
              // DBase file data.
              this.header = null;
              this.fields = null;
  
              // Internal use only. Intentionally not documented.
              // The buffer descriptor to read records from.
              this.buffer = null;
  
              // Internal use only. Intentionally not documented.
              // Source read parameters.
              this.boolean = true;
              this.numRecordsRead = 0;
  
              this._completionCallback = null;
          }
docs: Constructs an object for dBase file at a specified URL. Applications typically do not call this constructor.
  It is called by {@link {Shapefile} to read attributes for shapes.
  @alias DBaseFile
  @constructor
  @classdesc Parses a dBase file.
  @param {String} url The location of the dBase file.
  @throws {ArgumentError} If the specified URL is null or undefined.