code: func (net *Network) Lookup(targetID NodeID) []*Node {
  	return net.lookup(crypto.Keccak256Hash(targetID[:]), false)
  }
docs: // Lookup performs a network search for nodes close
  // to the given target. It approaches the target by querying
  // nodes that are closer to it on each iteration.
  // The given target does not need to be an actual node
  // identifier.
  //
  // The local node may be included in the result.