code: func (a *AddrBook) init() {
  	a.key = crypto.CRandHex(24) // 24/2 * 8 = 96 bits
  	// New addr buckets
  	a.addrNew = make([]map[string]*knownAddress, newBucketCount)
  	for i := range a.addrNew {
  		a.addrNew[i] = make(map[string]*knownAddress)
  	}
  	// Old addr buckets
  	a.addrOld = make([]map[string]*knownAddress, oldBucketCount)
  	for i := range a.addrOld {
  		a.addrOld[i] = make(map[string]*knownAddress)
  	}
  }
docs: // When modifying this, don't forget to update loadFromFile()