Item::offsetSetDirect

public function offsetSetDirect($offset, $value)
{
	if($this->isImmutable())
	{
		return; // todo: throw NotAllowedException?
	}

	$offset = trim((string) $offset);
	if($offset)
	{
		$data =& $this->getContextData();
		$data[$offset] = $value;
	}
}