# File lib/sup/modes/thread-index-mode.rb, line 732
  def hide_thread t
    @mutex.synchronize do
      i = @threads.index(t) or return
      raise "already hidden" if @hidden_threads[t]
      @hidden_threads[t] = true
      @threads.delete_at i
      @size_widgets.delete_at i
      @tags.drop_tag_for t
    end
  end