Represents an "addr" message on the P2P network, which contains broadcast IP addresses of other peers. This is
one of the ways peers can find each other without using the DNS or IRC discovery mechansisms. However storing and
using addr messages is not presently implemented.
This should be overridden to extract correct message size in the case of lazy parsing. Until this method is
implemented in a subclass of ChildMessage lazy parsing may have no effect.
This default implementation is a safe fall back that will ensure it returns a correct value by parsing the message.
Perform the most minimal parse possible to calculate the length of the message.
This is only required for subclasses of ChildClass as root level messages will have their length passed
into the constructor.
Implementations should adhere to the following contract: If parseLazy = true the 'length'
field must be set before returning. If parseLazy = false the length field must be set either
within the parseLite() method OR the parse() method. The overriding requirement is that length
must be set to non UNKNOWN_MESSAGE value by the time the constructor exits.