public int visitStatement(String statement) throws SQLException {
   if (nextVisitor == null) {
     return 0;
   } else {
     return nextVisitor.visitStatement(statement);
   }
 }
 public void doRollback() throws SQLException {
   if (nextVisitor != null) nextVisitor.doRollback();
 }
 public void doCommit() throws SQLException {
   if (nextVisitor != null) nextVisitor.doCommit();
 }
 public void visitComment(String theComment) throws SQLException {
   if (nextVisitor != null) nextVisitor.visitComment(theComment);
 }