marshaller.go
func (m *Marshaller) MarshalBytes(bs []byte) {
	if m.Error != nil {
		return
	}
	if len(m.Data) < m.offset+4+len(bs)+Padding(len(bs)) {
		m.Error = io.ErrShortBuffer
		return
	}

	m.MarshalUint32(uint32(len(bs)))
	m.offset += copy(m.Data[m.offset:], bs)
	m.offset += copy(m.Data[m.offset:], padBytes[:Padding(len(bs))])
}
func (m *Marshaller) MarshalBytes(bs []byte) {
	if m.Error != nil {
		return
	}
	if len(m.Data) < m.offset+4+len(bs)+Padding(len(bs)) {
		m.Error = io.ErrShortBuffer
		return
	}

	m.MarshalUint32(uint32(len(bs)))
	m.offset += copy(m.Data[m.offset:], bs)
	m.offset += copy(m.Data[m.offset:], padBytes[:Padding(len(bs))])
}
// MarshalString appends the bytes to the buffer, with a size prefix and
// correct padding.