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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 get(app: web.Application, feature_type: Type[Any] = None, key: Hashable = None ) -> Any: """ Finds declared feature. Identification is done based on feature type and key. Args: app (web.Application):
 The current Aiohttp application. feature_type (Type[Any]):
 The Python type of the desired feature. If specified, it will be checked against the found feature. key (Hashable):
 A specific identifier for the desired feature. Defaults to `feature_type` Returns: Any: The feature found for the combination of `feature_type` and `key` """

    key = key or feature_type

    if not key:
        raise AssertionError('No feature identifier provided')

    try:
        found = app[FEATURES_KEY][key]
    except KeyError:
        raise KeyError(f'No feature found for "{key}"')

    if feature_type and not isinstance(found, feature_type):
        raise AssertionError(f'Found {found} did not match type "{feature_type}"')

    return found