Redstone XML-RPC Library

I want to limit the amount of data sent to the client. I did this by doing, for example

public class Project extends RPCProject
{
private String someVarUsedInternally;
}

public class RPCProject
{
protected String what;
protected int I;
protected ArrayList want;
protected String client;
protected String toSee;
}

// RPC Exposed method
public RPCProject getProject()
{
return (RPCProject)projectInQuestion;
}


However, it seems to return the 'someVarUsedInternally' too..Any ideas?