client: {
    mandatory: {};
    optional: {
        OtaSoftwareUpdateRequestor: Type<OtaSoftwareUpdateRequestor.Cluster, Type<Of<{
            attributes: {};
            commands: {};
            events: {};
            id: 0;
            name: "Unknown";
            revision: 0;
        }>, typeof ClusterBehavior, OtaSoftwareUpdateRequestorInterface>, OtaSoftwareUpdateRequestorInterface>;
    };
} = ...

A definition for each client cluster supported by the endpoint per the Matter specification.