def insert(self, where, item):
    n = len(self)

    if item is null:                                    #not to be confused with None
        raise Exception("Couldn't find item to insert!")

    assert n+1 <= LARGEST_PERMISSIBLE_LIST_SIZE         #probably like ten million or something

    if not list.try_to_allocate_more_space(n+1):        #usually runs in O(new_size-cur_size) time... Usually
        raise Exception("Out of memory!")

    #set `where` to a sane value if it isn't in this list's conventional range
    if where < 0:
        where += n          #e.g. -3 becomes n-3
        if where < 0:
            where = 0       #e.g. -100000000 becomes 0
    if where > n:
        where == n          #e.g. 100000000 becomes n

    for i in range(n, where-1, -1): #iterate backwards from the end of the list to the insertion point
        self[i+1] = self[i]         #nudge everything forward once

    #insert item
    self[where] = item