These types are defined in [DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/lodash/lodash.d.ts#L16101), but are not located here. Because of this, the following is valid: ``` ts const items = _(someObj) .pickBy((item) => ...) .mapValues((item) => ...) .value(); ``` but this is invalid: ``` ts const items = _.chain(someObj) .pickBy((item) => ...) .mapValues((item) => ...) .value(); ```