@Override
  public void localUpdateAttribute(String name, Object value) {
    if (manager == null) {
      // Name cannot be null
      if (name == null) {
        throw new IllegalArgumentException(sm.getString("standardSession.setAttribute.namenull"));
      }

      // Null value is the same as removeAttribute()
      if (value == null) {
        removeAttribute(name);
        return;
      }

      // Validate our current state
      if (!isValidInternal()) {
        throw new IllegalStateException(
            sm.getString("standardSession.setAttribute.ise", getIdInternal()));
      }

      // Replace or add this attribute
      getAttributes().put(name, value);
    } else {
      // don't do notification since this is a replication
      super.setAttribute(name, value, false);
    }
  }
Return the <code>HttpSession</code> for which this object is the facade.
extensions/geode-modules/src/main/java/org/apache/geode/modules/session/catalina/DeltaSession.java