def part(channel, reason = nil)
      channel = Channel(channel)
      channel.part(reason)

      channel
    end
def part(channel, reason = nil)
      channel = Channel(channel)
      channel.part(reason)

      channel
    end
Part a channel.

 @param [String, Channel] channel either the name of a channel or a {Channel} object
 @param [String] reason an optional reason/part message
 @return [Channel] The channel that was left
 @see Channel#part