src := make([]byte, 10)
	eofR := &eofReader{buf: src}
	r := NewReader(eofR)

	// Start by reading 5 of the 10 available bytes.
	dest := make([]byte, 5)
	read, err := r.Read(dest)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if n := len(dest); read != n {
		t.Fatalf("read %d bytes; wanted %d bytes", read, n)
	}

	// The Reader should have buffered all the content from the io.Reader.