/**
* Initializes a new instance of that class.
*
* @param mixed $previousValue The value that was set via IItemContext::nextValue() in the context of
* the previous item.
*
* @param IEnumerable $seq The underlying sequence.
*/
public function __construct(IEnumerable $seq, $previousValue = null)
{
$this->_seq = $seq;
$this->_previousValue = $previousValue;
$this->_key = $this->_seq->key();
$this->_item = $this->_seq->current();
}
