ApiTaskResult<T>	A representation of the result of a `Task`, which includes additional information about the outcome of the execution.
TaskResultContracts	A collection of `ActivityResultContract`s to resolve `Task` objects.
TaskResultContracts.GetApiTaskResult<T>	A contract that takes a `Task<T>` and yields an `ApiTaskResult<T>` with the result and additional information about the operation.
TaskResultContracts.GetPaymentData	A simple contract that returns a `PaymentData` object.
TaskResultContracts.GetPaymentDataResult	A simple contract based on `TaskResultContracts.GetApiTaskResult` that returns a wrapper including a `PaymentData` object and additional information about the `Task` operation.
TaskResultContracts.ResolveApiTaskResult<I, O>	A contract that takes a `Task<I>` and yields a result `O`.
TaskResultContracts.UnpackApiTaskResult<T>	A contract that takes a `Task<T>` and optionally returns its result `T?` if the task completes successfully.

com.google.android.gms.wallet.contract