code: func (b *Bzz) UpdateLocalAddr(byteaddr []byte) *BzzAddr {
  	b.localAddr = b.localAddr.Update(&BzzAddr{
  		UAddr: byteaddr,
  		OAddr: b.localAddr.OAddr,
  	})
  	return b.localAddr
  }
docs: // UpdateLocalAddr updates underlayaddress of the running node