Encode a string using Consistent Overhead Byte Stuffing/Reduced (COBS/R).
    
    Input is any byte string. Output is also a byte string.
    
    Encoding guarantees no zero bytes in the output. The output
    string may be expanded slightly, by a predictable amount.
    
    An empty string is encoded to '\\x01

def encode(in_bytes):
    """Encode a string using Consistent Overhead Byte Stuffing/Reduced (COBS/R).
    
    Input is any byte string. Output is also a byte string.
    
    Encoding guarantees no zero bytes in the output. The output
    string may be expanded slightly, by a predictable amount.
    
    An empty string is encoded to '\\x01'"""
    if isinstance(in_bytes, str):
        raise TypeError('Unicode-objects must be encoded as bytes first')
    in_bytes_mv = _get_buffer_view(in_bytes)
    out_bytes = bytearray()
    idx = 0
    search_start_idx = 0
    for in_char in in_bytes_mv:
        if idx - search_start_idx == 0xFE:
            out_bytes.append(0xFF)
            out_bytes += in_bytes_mv[search_start_idx:idx]
            search_start_idx = idx
        if in_char == b'\x00':
            out_bytes.append(idx - search_start_idx + 1)
            out_bytes += in_bytes_mv[search_start_idx:idx]
            search_start_idx = idx + 1
        idx += 1
    try:
        final_byte_value = ord(in_bytes_mv[-1])
    except IndexError:
        final_byte_value = 0
    length_value = idx - search_start_idx + 1
    if final_byte_value < length_value:
        # Encoding same as plain COBS
        out_bytes.append(length_value)
        out_bytes += in_bytes_mv[search_start_idx:idx]
    else:
        # Special COBS/R encoding: length code is final byte,
        # and final byte is removed from data sequence.
        out_bytes.append(final_byte_value)
        out_bytes += in_bytes_mv[search_start_idx:idx - 1]
    return bytes(out_bytes)