ifelse([$2],,,[PECL_HAVE_VERSION(libevent, [$2])])
AC_CHECK_FUNC(event_base_new,,[
AC_DEFINE([event_base_new], [event_init], [missing event_base_new() in libevent1])
ifelse([$2],,,[PECL_HAVE_VERSION(libevent, [$2])])
AC_CHECK_FUNC(event_base_new,,[
AC_DEFINE([event_base_new], [event_init], [missing event_base_new() in libevent1])