code: func (fds *FDSet) Clear(fd uintptr) {
  	var i uint
  	for i = 0; i < fds.fd_count; i++ {
  		if fds.fd_array[i] == fd {
  			for i < fds.fd_count-1 {
  				fds.fd_array[i] = fds.fd_array[i+1]
  				i++
  			}
  			fds.fd_count--
  			break
  		}
  	}
  }
docs: // Clear remove the fd from the set