if (this.addresses.containsKey(otherKey)) {
                    if (!this.addresses.get(otherKey).equals(otherValue)
                            && !overwrite
                            && log != null) {
                        log.append("Conflict for " + otherKey + " from "
                                + other.location
                                + ". Destination in remote address book is "
                                + otherValue);
                    }
                } 
                else
                {
                        this.addresses.put(otherKey, otherValue);
                        this.modified = true;
                        if (log != null) {
                            log.append("New address " + otherKey
                                + " added to address book.");
                        }
                    }  
                }