nodeLiveFieldExtract "mfree" res =
  jsonHead (rpcResNodeInfoHvInfo res) hvInfoMemoryFree
nodeLiveFieldExtract "mfree" res =
  jsonHead (rpcResNodeInfoHvInfo res) hvInfoMemoryFree
nodeLiveFieldExtract "mfree" res =
  jsonHead (rpcResNodeInfoHvInfo res) hvInfoMemoryFree