docs: private final Object invokeOnDB2Connection(Connection con, AtomicReference<Method> methRef,
                                                 String methName, Class<?>[] paramTypes, Object... params) throws SQLException {
          try {
              Method m = methRef.get();
              if (m == null) {
                  Class<?> c = WSManagedConnectionFactoryImpl.priv.loadClass(mcf.jdbcDriverLoader, "com.ibm.db2.jcc.DB2Connection");
                  methRef.set(m = c.getMethod(methName, paramTypes));
              }
  
              return m.invoke(con, params);
          } catch (RuntimeException x) {
              throw x;
          } catch (NoSuchMethodException x) {
              throw (Error) new NoSuchMethodError(methName).initCause(x);
          } catch(InvocationTargetException e){
              throw AdapterUtil.toSQLException(e.getCause());
          } catch (Exception x) {
              throw AdapterUtil.toSQLException(x);
          }
      }