@classmethod
def from_machine_readable(cls, machine_readable, evidence=None):
    """
        xarf factory to create xarf object from dict.

        :param machine_readable: xarf machine readable part
        :type machine_readable: dict
        :param evidence: raw evidence data
        :type evidence: string

        :returns: instance of :py:class:`Xarf`
        :rtype: instance

        """
    data = {}
    for key in machine_readable:
        valid_key = key.lower().replace('-', '_')
        data[valid_key] = machine_readable[key]
    data['evidence'] = evidence
    return cls(**data)
