@DefinedBy(Api.COMPILER)
    public JavaFileObject getSource() {
        if (source == null)
            return null;
        else
            return source.getFile();
    }
@ DefinedBy ( Api . COMPILER ) public JavaFileObject getSource ( ) { if ( source == null ) return null ; else return source . getFile ( ) ; }
Get the name of the source file referred to by this diagnostic.
@return the name of the source referred to with this diagnostic, or null if none