def to_dict(self):
return {<EOL>"<STR_LIT:type>": self.type,<EOL>"<STR_LIT:name>": self.name,<EOL>"<STR_LIT>": self.group_by_key,<EOL>"<STR_LIT>": self.role,<EOL>"<STR_LIT>": self.units,<EOL>"<STR_LIT>": self.build_options()<EOL>}<EOL>
Converts the column to a dictionary representation accepted
by the Citrination server.

:return: Dictionary with basic options, plus any column type specific
    options held under the "options" key
:rtype: dict