if (sfContext.containsKey(name)) { return null; }
if (sfContext != null) { if (sfContext.containsKey(name)) { return null; }
    public synchronized Object sfAddAttribute(Object name, Object value)        throws SmartFrogRuntimeException, RemoteException {        if ((name == null) || (value == null)) {          if (name == null) {              throw new SmartFrogRuntimeException(              MessageUtil.formatMessage(MSG_NULL_DEF_METHOD, "'name'",                                        "sfAddAttribute"), this);          }          if (value == null) {              throw new SmartFrogRuntimeException(              MessageUtil.formatMessage(MSG_NULL_DEF_METHOD, "'value'",                                        "sfAddAttribute"), this);          }            return null;        }        if (sfContext.containsKey(name)) {            return null;        }        sfContext.put(name, value);        return value;    }