class Address : public QObject {
     public:
          void validate(const ConnectionInfo &info);
[...]
};

class AddressValidator : public WebAPICall {
	public:
		AddressValidator(const ConnectionInfo & info, Address const &OldAddress, Address &NewAddress, QWidget *parent = 0);
[...]
};

void Address::validate( const ConnectionInfo & info )
{
	AddressValidator validator(info,*this,*this,this);
[...]
}