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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def filter_event(tag, data, defaults):
    '''
    Accept a tag, a dict and a list of default keys to return from the dict, and
    check them against the cloud configuration for that tag
    '''
    ret = {}
    keys = []
    use_defaults = True

    for ktag in __opts__.get('filter_events', {}):
        if tag != ktag:
            continue
        keys = __opts__['filter_events'][ktag]['keys']
        use_defaults = __opts__['filter_events'][ktag].get('use_defaults', True)

    if use_defaults is False:
        defaults = []

    # For PY3, if something like ".keys()" or ".values()" is used on a dictionary,
    # it returns a dict_view and not a list like in PY2. "defaults" should be passed
    # in with the correct data type, but don't stack-trace in case it wasn't.
    if not isinstance(defaults, list):
        defaults = list(defaults)

    defaults = list(set(defaults + keys))

    for key in defaults:
        if key in data:
            ret[key] = data[key]

    return ret