# File lib/ffi-rzmq/poll_item.rb, line 18
    def self.from_pollable(pollable)
      item = self.new
      item.pollable = pollable
      case
      when pollable.respond_to?(:socket)
        item.socket = pollable.socket
      when pollable.respond_to?(:posix_fileno)
        item.fd = pollable.posix_fileno
      when pollable.respond_to?(:io)
        item.fd = pollable.io.posix_fileno
      end
      item
    end