public void nextToken(int start) {
        token = scanner.previousToken(start - 1, SQLHeuristicScanner.UNBOUND);
        position = scanner.getPosition() + 1;
        try {
            line = document.getLineOfOffset(position);
        } catch (BadLocationException e) {
            line = -1;
        }
    }
Reads the next token in backward direction from the heuristic scanner and sets the fields
<code>fToken, fPreviousPosition</code> and <code>fPosition</code> accordingly.
plugins/org.jkiss.dbeaver.ui.editors.sql/src/org/jkiss/dbeaver/ui/editors/sql/indent/SQLIndenter.java