This function is used when a Plaintext needs to be sent via a edu.biu.scapi.comm.Channel or any other means of sending data (including serialization).
It retrieves all the data needed to reconstruct this Plaintext at a later time and/or in a different VM. It puts all the data in an instance of the
relevant class that implements the PlaintextSendableData interface.
In order to deserialize this into a BigIntegerPlainText all you need to do is cast the serialized object with (BigIntegerPlainText)