Get the requested domain
        @param  dname:  Domain name
        @type   dname:  str
        @rtype: Domain or None

def get(cls, dname):
        """
        Get the requested domain
        @param  dname:  Domain name
        @type   dname:  str
        @rtype: Domain or None
        """
        Domain = cls
        dname = dname.hostname if hasattr(dname, 'hostname') else dname.lower()
        return Session.query(Domain).filter(Domain.name == dname).first()