Type alias Subset<K>

Subset<K>: {
    [attr in keyof K]?: K[attr] extends object
        ? Subset<K[attr]>
        : K[attr] extends object | null
            ? Subset<K[attr]> | null
            : K[attr] extends object | null | undefined
                ? Subset<K[attr]> | null | undefined
                : K[attr]
}

A better "Partial" type that makes all properties optional, including nested ones.