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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def genlmsg_put(msg, port, seq, family, hdrlen, flags, cmd, version):
 """Add Generic Netlink headers to Netlink message. https://github.com/thom311/libnl/blob/libnl3_2_25/lib/genl/genl.c#L348 Calls nlmsg_put() on the specified message object to reserve space for the Netlink header, the Generic Netlink header, and a user header of specified length. Fills out the header fields with the specified parameters. Positional arguments: msg -- Netlink message object (nl_msg class instance). port -- Netlink port or NL_AUTO_PORT (c_uint32). seq -- sequence number of message or NL_AUTO_SEQ (c_uint32). family -- numeric family identifier (integer). hdrlen -- length of user header (integer). flags -- additional Netlink message flags (integer). cmd -- numeric command identifier (c_uint8). version -- interface version (c_uint8). Returns: bytearray starting at user header or None if an error occurred. """

    hdr = genlmsghdr(cmd=cmd, version=version)
    nlh = nlmsg_put(msg, port, seq, family, GENL_HDRLEN + hdrlen, flags)
    if nlh is None:
        return None
    nlmsg_data(nlh)[:hdr.SIZEOF] = hdr.bytearray[:hdr.SIZEOF]
    _LOGGER.debug('msg 0x%x: Added generic netlink header cmd=%d version=%d', id(msg), cmd, version)
    return bytearray_ptr(nlmsg_data(nlh), GENL_HDRLEN)