--- /dev/null
+namespace System.IO
+{
+ partial class Stream
+ {
+ public virtual int Read (Span<byte> destination)
+ {
+ throw new NotImplementedException ();
+ }
+
+ public virtual void Write(ReadOnlySpan<byte> source)
+ {
+ throw new NotImplementedException ();
+ }
+ }
+}
\ No newline at end of file