docs: public synchronized Statement getStatement(Session session, long csid) {
  
          Statement cs = (Statement) csidMap.get(csid);
  
          if (cs == null) {
              return null;
          }
  
          if (!cs.isValid()) {
              String sql = (String) sqlLookup.get(csid);
  
              // revalidate with the original schema
              try {
                  Session sys = database.sessionManager.getSysSession(
                      session.currentSchema.name, session.getUser());
  
                  cs = sys.compileStatement(sql);
  
                  cs.setID(csid);
                  csidMap.put(csid, cs);
              } catch (Throwable t) {
                  freeStatement(csid, session.getId(), true);
  
                  return null;
              }
          }
  
          return cs;
      }