public SynchronizedStatement add(final SynchronizedDb db, final String name, final String sql) {
   SynchronizedStatement stmt = db.compileStatement(sql);
   SynchronizedStatement old = mStatements.get(name);
   mStatements.put(name, stmt);
   if (old != null) old.close();
   return stmt;
 }
 public void close() {
   synchronized (mStatements) {
     for (SynchronizedStatement s : mStatements.values()) {
       try {
         s.close();
       } catch (Exception e) {
       }
       ;
     }
     mStatements.clear();
   }
 }