class CFileDataSource {CFileDataSource(URL& url, std::vector<uint16_t> exclusionList);CRingItem* getItem();}
            Provides a source of ring items from a file.  For information about
            how to directly create and use this object see METHODS
            below.  The normal way to create a data source object, however is to
            use CDataSourceFactory to create the correct
            type of data source from a URI
          
  CFileDataSource(URL& url, std::vector<uint16_t> exclusionList);
                        Creates a file data source.
                        url determines which file data
                        will be read from.  The url must have a
                        file: protocol specified.
                    
                        exclusionList is a list of data
                        item types that will not be passed to the caller
                        by getItem.
                    
  CRingItem* getItem();
                        Gets the next ring item from the file whose type is not
                        a type in the construtor's exclusionList.