function override(keyword, value) {
	const retv = {
		before: value.before === false,
		after: value.after === false,
		overrides: {},
	};

	retv.overrides[keyword] = value;

	return retv;
}
Creates an option object to test an "overrides" option.

e.g.

    override("as", BOTH)

returns

    {
        before: false,
        after: false,
        overrides: {as: {before: true, after: true}}
    }
@param {string} keyword A keyword to be overridden.
@param {Object} value A value to override.
@returns {Object} An option object to test an "overrides" option.