MutationState
interface MutationState <TData = unknown, TError = unknown, TVariables = void, TContext = unknown> {
context: TContext | undefined;
data: TData | undefined;
error: TError | null;
failureCount: number;
failureReason: TError | null;
isPaused: boolean;
status: MutationStatus;
variables: TVariables | undefined;
}