code: def _read_mptcp_fastclose(self, bits, size):
          
          ____ = self._read_fileng(1)
          rkey = self._read_fileng(8)
  
          data = dict(
              subtype='MP_FASTCLOSE',
              fastclose=dict(
                  rkey=rkey,
              ),
          )
  
          return data
docs: Read Fast Close option.
  
          Positional arguments:
              * bits - str, 4-bit data
              * size - int, length of option
  
          Returns:
              * dict -- extracted Fast Close (MP_FASTCLOSE) option
  
          Structure of MP_FASTCLOSE [RFC 6824]:
                                   1                   2                   3
               0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
              +---------------+---------------+-------+-----------------------+
              |     Kind      |    Length     |Subtype|      (reserved)       |
              +---------------+---------------+-------+-----------------------+
              |                      Option Receiver's Key                    |
              |                            (64 bits)                          |
              |                                                               |
              +---------------------------------------------------------------+
  
              Octets      Bits        Name                        Description
                0           0     tcp.opt.kind                Kind (30)
                1           8     tcp.opt.length              Length (12)
                2          16     tcp.opt.mp.subtype          Subtype (7)
                2          23     -                           Reserved (must be zero)
                4          32     tcp.opt.mp.fastclose.rkey   Option Receiver's Key