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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 Browser(driver_name="firefox", *args, **kwargs):
 """ Returns a driver instance for the given name. When working with ``firefox``, it's possible to provide a profile name and a list of extensions. If you don't provide any driver_name, then ``firefox`` will be used. If there is no driver registered with the provided ``driver_name``, this function will raise a :class:`splinter.exceptions.DriverNotFoundError` exception. """


    try:
        driver = _DRIVERS[driver_name]
    except KeyError:
        raise DriverNotFoundError("No driver for %s" % driver_name)
    return driver(*args, **kwargs)