def read_header(socket)
      header = ::ROS::TCPROS::Header.new
      header.deserialize(read_all(socket))
      header
    end
def read_header(socket)
      header = ::ROS::TCPROS::Header.new
      header.deserialize(read_all(socket))
      header
    end
read a connection header from socket
 @param [String] socket socket for reading
 @return [Header] header