Generates a useful node from the data provided.

def _make_node(self, singular, plural, variables, plural_expr,
                   vars_referenced, num_called_num):
        """Generates a useful node from the data provided."""
        # no variables referenced?  no need to escape for old style
        # gettext invocations only if there are vars.
        if not vars_referenced and not self.environment.newstyle_gettext:
            singular = singular.replace('%%', '%')
            if plural:
                plural = plural.replace('%%', '%')

        # singular only:
        if plural_expr is None:
            gettext = nodes.Name('gettext', 'load')
            node = nodes.Call(gettext, [nodes.Const(singular)],
                              [], None, None)

        # singular and plural
        else:
            ngettext = nodes.Name('ngettext', 'load')
            node = nodes.Call(ngettext, [
                nodes.Const(singular),
                nodes.Const(plural),
                plural_expr
            ], [], None, None)

        # in case newstyle gettext is used, the method is powerful
        # enough to handle the variable expansion and autoescape
        # handling itself
        if self.environment.newstyle_gettext:
            for key, value in iteritems(variables):
                # the function adds that later anyways in case num was
                # called num, so just skip it.
                if num_called_num and key == 'num':
                    continue
                node.kwargs.append(nodes.Keyword(key, value))

        # otherwise do that here
        else:
            # mark the return value as safe if we are in an
            # environment with autoescaping turned on
            node = nodes.MarkSafeIfAutoescape(node)
            if variables:
                node = nodes.Mod(node, nodes.Dict([
                    nodes.Pair(nodes.Const(key), value)
                    for key, value in variables.items()
                ]))
        return nodes.Output([node])