if b.String() != "<nil>" {
		t.Errorf("expected <nil>; got %q", b.String())
	}
}

func TestReadFrom(t *testing.T) {
	var buf Buffer
	for i := 3; i < 30; i += 3 {
		s := fillBytes(t, "TestReadFrom (1)", &buf, "", 5, testBytes[:len(testBytes)/i])
		var b Buffer
		b.ReadFrom(&buf)
		empty(t, "TestReadFrom (2)", &b, s, make([]byte, len(testString)))
	}
}

type panicReader struct{ panic bool }