"github.com/minio/minio/internal/hash/sha256"
	"github.com/minio/minio/internal/ioutil"
)

// A Reader wraps an io.Reader and computes the MD5 checksum
// of the read content as ETag. Optionally, it also computes
// the SHA256 checksum of the content.
//
// If the reference values for the ETag and content SHA26
// are not empty then it will check whether the computed
// match the reference values.
type Reader struct {