def range_closest(ranges, b, left=True):
    """
    Returns the range that's closest to the given position. Notice that the
    behavior is to return ONE closest range to the left end (if left is True).
    This is a SLOW method.

    >>> ranges = [("1", 30, 40), ("1", 33, 35), ("1", 10, 20)]
    >>> b = ("1", 22, 25)
    >>> range_closest(ranges, b)
    ('1', 10, 20)
    >>> range_closest(ranges, b, left=False)
    ('1', 33, 35)
    >>> b = ("1", 2, 5)
    >>> range_closest(ranges, b)
    """
    from jcvi.utils.orderedcollections import SortedCollection
    key = (lambda x: x) if left else (lambda x: (x[0], x[2], x[1]))
    rr = SortedCollection(ranges, key=key)
    try:
        if left:
            s = rr.find_le(b)
            assert key(s) <= key(b), (s, b)
        else:
            s = rr.find_ge(b)
            assert key(s) >= key(b), (s, b)
    except ValueError:
        s = None

    return s