def __init__(self, **kwargs):
        """Initializes the Jinja2 Environment object while loading extensions.
        Does the following:

        1. Establishes default_extensions (currently just a Time feature)
        2. Reads extensions set in the cookiecutter.json _extensions key.
        3. Attempts to load the extensions. Provides useful error if fails.
        """
        context = kwargs.pop('context', {})

        default_extensions = [
            'jinja2_time.TimeExtension',
        ]
        extensions = default_extensions + self._read_extensions(context)

        try:
            super(ExtensionLoaderMixin, self).__init__(
                extensions=extensions,
                **kwargs
            )
        except __HOLE__ as err:
            raise UnknownExtension('Unable to load extension: {}'.format(err))
dataset/ETHPy150Open audreyr/cookiecutter/cookiecutter/environment.py/ExtensionLoaderMixin.__init__