n2, err := w.ReadFrom(r)
	if n2 != 4 || err != nil {
		t.Fatalf("ReadFrom returned (%v, %v), want (4, nil)", n2, err)
	}
	w.Flush()
	if got, want := buf.String(), "0123abcd"; got != want {
		t.Fatalf("buf.Bytes() returned %q, want %q", got, want)
	}
}

func TestWriterReadFromErrNoProgress(t *testing.T) {
	buf := new(bytes.Buffer)
	w := NewWriterSize(buf, 5)

		}
	}
}

var EqualFoldTests = []struct {
	s, t string
	out  bool
}{
	{"abc", "abc", true},
	{"ABcd", "ABcd", true},
	{"123abc", "123ABC", true},
	{"αβδ", "ΑΒΔ", true},
	{"abc", "xyz", false},
	{"abc", "XYZ", false},
	{"abcdefghijk", "abcdefghijX", false},
	{"abcdefghijk", "abcdefghij\u212A", true},