code: func (pm *ProtocolManager) NodeInfo() *NodeInfo {
  	currentBlock := pm.blockchain.CurrentBlock()
  	return &NodeInfo{
  		Network:    pm.networkID,
  		Difficulty: pm.blockchain.GetTd(currentBlock.Hash(), currentBlock.NumberU64()),
  		Genesis:    pm.blockchain.Genesis().Hash(),
  		Config:     pm.blockchain.Config(),
  		Head:       currentBlock.Hash(),
  	}
  }
docs: // NodeInfo retrieves some protocol metadata about the running host node.