Generates a new column from the given json data.  This should
        be already loaded into a Python dictionary, not a JSON string.

        :param      jdata | <dict>

        :return     <orb.Column> || None

def fromJSON(cls, jdata):
        """
        Generates a new column from the given json data.  This should
        be already loaded into a Python dictionary, not a JSON string.

        :param      jdata | <dict>

        :return     <orb.Column> || None
        """
        cls_type = jdata.get('type')
        col_cls = cls.byName(cls_type)

        if not col_cls:
            raise orb.errors.ColumnTypeNotFound(cls_type)
        else:
            col = col_cls()
            col.loadJSON(jdata)
            return col