clojure.lang.EnumeratorSeq.rest C# (CSharp) Method

        public override ISeq rest()
        {
            if ( _state._rest == _state )
                lock (_state)
                {
                    if (_state._rest == _state)
                    {
                        first();
                        _state._rest = _enumerator.MoveNext() ? new EnumeratorSeq(_enumerator) : null;
                        // Java: _state._rest = create(_enumerator);

                    }
                }
            return (ISeq)_state._rest;
        }