@classmethod
def add_op2_data(cls, data, comment=''):
    """
        Adds a CPLSTN6 card from the OP2

        Parameters
        ----------
        data : List[varies]
            a list of fields defined in OP2 format
        comment : str; default=''
            a comment for the card

        """
    eid = data[0]
    pid = data[1]
    nids = data[2:8]
    theta = data[8]
    assert len(nids) == 6, 'error on CPLSTN6'
    return cls(eid, pid, nids, theta, comment=comment)
