Simplest required implementation of collections.Counter. Required as 2.6
    does not have Counter in collections.

def counter(items):
    """
    Simplest required implementation of collections.Counter. Required as 2.6
    does not have Counter in collections.
    """
    results = {}
    for item in items:
        results[item] = results.get(item, 0) + 1
    return results