'Return :class:`.Algorithm` based on the value.
:param value: Algorithm name (e.g. http, tcp, ...).
:type  value: ``str``
:rtype: :class:`.Algorithm`'

def _value_to_algorithm(self, value):

    try:
        return self._VALUE_TO_ALGORITHM_MAP[value]
    except KeyError:
        raise LibcloudError(value=('Invalid    value:    %s' % value), driver=self)
