def maybeFlatten(items):
    """
    Iterate through top-level lists
    Flatten, only if the element is also a list

    [[1,2],3,[[4,5]]] -> [1,2,3,[4,5]]
    """
    new_list = []
    for elem in items:
        if isinstance(elem, list):
            new_list.extend(elem)
        else:
            new_list.append(elem)
    return new_list
