What are the issues with the following implementation of delete item on an unsorted linked list? You can assume self.head points to the node at the beginning of the list and each node has a link variable that refers to the next node in the list (or None if it's the last node).

def __delitem__(self, key) -> None:
    if self.is_empty():
        raise ValueError("Can't delete from an empty list")
        
    previous = None
    current = self.head
    for _ in range(len(self)):
        if current.item == key:
            current = previous.link
        else:
            previous = current
        current = current.link