add placeholders for .x, .group_key, and .rtv

nmdefries · nmdefries · commit 620648e79a4b · 2023-06-05T15:23:57.000-04:00
diff --git a/R/epiprocess.R b/R/epiprocess.R
@@ -7,3 +7,4 @@
 #' @docType package
 #' @name epiprocess
 NULL
+utils::globalVariables(c(".x", ".group_key", ".ref_time_value"))
