def single_node_facts(node, facts)
      fields = Hash[facts.collect { |fact| [fact.to_sym, 1] }]
      collection = connection[nodes_collection]
      result = collection.find(_id: node).limit(1).batch_size(1).projection(fields).to_a.first
      result.delete("_id") if result
      result
    end
def single_node_facts(node, facts)
      fields = Hash[facts.collect { |fact| [fact.to_sym, 1] }]
      collection = connection[nodes_collection]
      result = collection.find(_id: node).limit(1).batch_size(1).projection(fields).to_a.first
      result.delete("_id") if result
      result
    end
get facts for given node name

 @param node [String] node name
 @param facts [Array<String>] get these facts in the result, eg ['fqdn'], empty for all