code: public E setGlobal(E value)
    {
      E oldValue = _globalValue;
  
      _globalValue = value;
  
      ClassLoader systemLoader = getSystemClassLoader();
  
      if (systemLoader instanceof EnvironmentClassLoader)
        ((EnvironmentClassLoader) systemLoader).setAttribute(_varName, value);
      else
        _globalValue = value;
  
      return oldValue;
    }
docs: Sets the global value.
  
  @param value
  the new value
  
  @return the old value