}
		}
		// Unread one byte if there is one.
		if n > 0 {
			if err := r.UnreadByte(); err != nil {
				t.Errorf("n = %d: unexpected error on UnreadByte: %v", n, err)
			}
		}
		// Test that we cannot unread any further.
		if err := r.UnreadByte(); err == nil {
			t.Errorf("n = %d: expected error on UnreadByte", n)
		}
	}
}

func TestUnreadByteOthers(t *testing.T) {