def to_json
      @threads.map do |t|
        {
          name: t.name,
          status: t.status,
          alive: t.alive?,
          vars: Hash[t.thread_variables.map { |v| [v.to_s, t.thread_variable_get(v)] }]
        }
      end
    end
def to_json
      @threads.map do |t|
        {
          name: t.name,
          status: t.status,
          alive: t.alive?,
          vars: Hash[t.thread_variables.map { |v| [v.to_s, t.thread_variable_get(v)] }]
        }
      end
    end
As a hash map