code: func (b *Buffer) AppendByte(data byte) {
  	if cap(b.Buf) == len(b.Buf) { // EnsureSpace won't be inlined.
  		b.EnsureSpace(1)
  	}
  	b.Buf = append(b.Buf, data)
  }
docs: // AppendByte appends a single byte to buffer.