Add comments to mockExecCommandInContainerForTotalStorageBytes in pkg/ddc/alluxio/ufs_test.go

[camellia-sad]

Which function do you want to add comments to?

mockExecCommandInContainerForTotalStorageBytes in fluid/pkg/ddc/alluxio/ufs_test.go

What comments do you want to add?

// mockExecCommandInContainerForTotalStorageBytes mocks command execution output for total storage bytes.
// This helper returns a fixed stdout payload that mimics the "du"-style summary used by tests.
//
// Parameters:
//   - none
//
// Returns:
//   - stdout (string): Mocked command output including file count, folder count, and folder size.
//   - stderr (string): Empty string because this mock simulates successful execution.
//   - err (error): Always nil for the success-path test scenario.