/// <summary>
/// Close the target.
/// </summary>
private void CloseTarget()
{
Debug.Assert(_target != null);
_target.Dispose();
_target = null;
}
/// <summary>
/// Get target enumerator.
/// </summary>
/// <returns>Target enumerator.</returns>
private void CreateTarget()
{
Debug.Assert(_target == null, "Previous target is not cleaned.");
_target = _cache.CreateEnumerator(_loc, _peekModes);
}