def build_options(self):
return None<EOL>
Default value for optional column configuration. Only child
classes will have non-None values for this field. Value
depends on child class implementation.

Note: Some child classes do not require any extra options
(e.g. OrganicChemicalFormula), in that case, this implementation
will be invoked and no options will be present in the dictionary.

:return: Options dictionary, or None if not implemented in child
:rtype: dict or None