Lookup value for a PluginOption instance

        Args:
            po: PluginOption

        Returns: converted value

def get(self, po):
        """Lookup value for a PluginOption instance

        Args:
            po: PluginOption

        Returns: converted value
        """
        name = po.name
        typ = po.typ
        default = po.default

        handler = getattr(self, '_get_{}'.format(typ), None)
        if handler is None:
            raise ValueError(typ)
        self.seen.add(name)

        # pylint: disable=not-callable
        if not self.parser.has_option(self.section, name):
            if default is REQUIRED:
                raise NameError(self.section, name)
            if isinstance(default, INHERIT_GLOBAL):
                return handler('global', name, default.default)
            # don't return default here, give the handler a chance to modify
            # the default, e.g. pw_uid with default='root' returns 0.

        return handler(self.section, name, default)