def single_node_facts(node)
      json = get_json("#{@nodes_url}/#{node}/facts", 10)
      return nil if json.include?("error")
      Hash[json.map { |data| [data["name"], data["value"]] }]
    end
def single_node_facts(node)
      json = get_json("#{@nodes_url}/#{node}/facts", 10)
      return nil if json.include?("error")
      Hash[json.map { |data| [data["name"], data["value"]] }]
    end
get hash of facts for given node name