Add highcharter example for varying virtual corpora

Change-Id: I97de60fdc3d0b6f397661099f08da8fccc2f45d4
diff --git a/R/highcharter-helper.R b/R/highcharter-helper.R
index cff6093..b33689a 100644
--- a/R/highcharter-helper.R
+++ b/R/highcharter-helper.R
@@ -17,6 +17,18 @@
 #'                  as.alternatives = TRUE) %>%
 #'   hc_freq_by_year_ci(as.alternatives = TRUE)
 #'
+#' kco <- new("KorAPConnection", verbose = TRUE)
+#' expand_grid(
+#'   condition = c("textDomain = /Wirtschaft.*/", "textDomain != /Wirtschaft.*/"),
+#'   year = (2005:2011)
+#' ) %>%
+#'   cbind(frequencyQuery(
+#'     kco,
+#'     "[tt/l=Heuschrecke]",
+#'     paste0(.$condition, " & pubDate in ", .$year)
+#'   ))  %>%
+#'   hc_freq_by_year_ci()
+#'
 hc_freq_by_year_ci <- function(df, as.alternatives = F, ylabel = if(as.alternatives) "%" else "ipm") {
   title <- ""
   df <- df %>%
diff --git a/man/hc_freq_by_year_ci.Rd b/man/hc_freq_by_year_ci.Rd
index 2ff1a52..8daa145 100644
--- a/man/hc_freq_by_year_ci.Rd
+++ b/man/hc_freq_by_year_ci.Rd
@@ -28,4 +28,16 @@
                  as.alternatives = TRUE) \%>\%
   hc_freq_by_year_ci(as.alternatives = TRUE)
 
+kco <- new("KorAPConnection", verbose = TRUE)
+expand_grid(
+  condition = c("textDomain = /Wirtschaft.*/", "textDomain != /Wirtschaft.*/"),
+  year = (2005:2011)
+) \%>\%
+  cbind(frequencyQuery(
+    kco,
+    "[tt/l=Heuschrecke]",
+    paste0(.$condition, " & pubDate in ", .$year)
+  ))  \%>\%
+  hc_freq_by_year_ci()
+
 }