// is implementation-dependent.
type Seeker interface {
	Seek(offset int64, whence int) (int64, error)
}

// ReadWriter is the interface that groups the basic Read and Write methods.
type ReadWriter interface {
	Reader
	Writer
}

// ReadCloser is the interface that groups the basic Read and Close methods.
type ReadCloser interface {
	Reader
	Closer
}

   *
   * <pre>
   * com....PotentialDeadlockException: Potential Deadlock from LockC -&gt; ReadWriteA
   *   at ...
   *   at ...
   * Caused by: com...ExampleStackTrace: LockB -&gt; LockC
   *   at ...
   *   at ...
   * Caused by: com...ExampleStackTrace: ReadWriteA -&gt; LockB
   *   at ...
   *   at ...
   * </pre>
   *

pkg bufio, method (*Writer) AvailableBuffer() []uint8
pkg bufio, method (ReadWriter) AvailableBuffer() []uint8
pkg bytes, func Cut([]uint8, []uint8) ([]uint8, []uint8, bool)
pkg bytes, func Title //deprecated
pkg crypto/tls, method (*Conn) NetConn() net.Conn
pkg crypto/tls, type Config struct, PreferServerCipherSuites //deprecated
pkg crypto/x509, method (*CertPool) Subjects //deprecated
pkg debug/buildinfo, func Read(io.ReaderAt) (*debug.BuildInfo, error)

		{"(ReadWriter).ReadRune", Method, 0},
		{"(ReadWriter).ReadSlice", Method, 0},
		{"(ReadWriter).ReadString", Method, 0},
		{"(ReadWriter).UnreadByte", Method, 0},
		{"(ReadWriter).UnreadRune", Method, 0},
		{"(ReadWriter).Write", Method, 0},
		{"(ReadWriter).WriteByte", Method, 0},
		{"(ReadWriter).WriteRune", Method, 0},
		{"(ReadWriter).WriteString", Method, 0},
		{"(ReadWriter).WriteTo", Method, 1},
		{"ErrAdvanceTooFar", Var, 1},

   *
   * <pre>
   * com....PotentialDeadlockException: Potential Deadlock from LockC -&gt; ReadWriteA
   *   at ...
   *   at ...
   * Caused by: com...ExampleStackTrace: LockB -&gt; LockC
   *   at ...
   *   at ...
   * Caused by: com...ExampleStackTrace: ReadWriteA -&gt; LockB
   *   at ...
   *   at ...
   * </pre>
   *

		fl |= flag(dst.Kind())
		return Value{dst, v.ptr, fl}

	case implements(dst, v.typ()):
		if target == nil {
			target = unsafe_New(dst)
		}
		if v.Kind() == abi.Interface && v.IsNil() {
			// A nil ReadWriter passed to nil Reader is OK,
			// but using ifaceE2I below will panic.
			// Avoid the panic by returning a nil dst (e.g., Reader) explicitly.
			return Value{dst, nil, flag(abi.Interface)}
		}
		x := valueInterface(v)

const (
	AzureDataDiskCachingNone      AzureDataDiskCachingMode = "None"
	AzureDataDiskCachingReadOnly  AzureDataDiskCachingMode = "ReadOnly"
	AzureDataDiskCachingReadWrite AzureDataDiskCachingMode = "ReadWrite"

	AzureSharedBlobDisk    AzureDataDiskKind = "Shared"
	AzureDedicatedBlobDisk AzureDataDiskKind = "Dedicated"
	AzureManagedDisk       AzureDataDiskKind = "Managed"
)

}

func TestReadAtLeastWithDataAndError(t *testing.T) {
	var rb dataAndErrorBuffer
	rb.err = fmt.Errorf("fake error")
	testReadAtLeast(t, &rb)
}

func testReadAtLeast(t *testing.T, rb ReadWriter) {
	rb.Write([]byte("0123"))
	buf := make([]byte, 2)
	n, err := ReadAtLeast(rb, buf, 2)
	if err != nil {
		t.Error(err)
	}
	if n != 2 {
		t.Errorf("expected to have read 2 bytes, got %v", n)
	}

	go spc.copyFromBackend(errc)
	<-errc
}

// switchProtocolCopier exists so goroutines proxying data back and
// forth have nice names in stacks.
type switchProtocolCopier struct {
	user, backend io.ReadWriter
}

func (c switchProtocolCopier) copyFromBackend(errc chan<- error) {
	_, err := io.Copy(c.user, c.backend)
	errc <- err
}

func (c switchProtocolCopier) copyToBackend(errc chan<- error) {

   * long, long)} using the requested {@link MapMode}.
   *
   * <p>Files are mapped from offset 0 to {@code size}.
   *
   * <p>If the mode is {@link MapMode#READ_WRITE} and the file does not exist, it will be created
   * with the requested {@code size}. Thus this method is useful for creating memory mapped files
   * which do not yet exist.
   *