diff --git a/tests/testthat/test-l_pkconc.R b/tests/testthat/test-l_pkconc.R
index bc734eb..8664be2 100644
--- a/tests/testthat/test-l_pkconc.R
+++ b/tests/testthat/test-l_pkconc.R
@@ -35,62 +35,74 @@ describe("l_pkconc", {
                             displaying_vars = c("NFRLT", "AFRLT", "AVAL"))
     expect_length(listings_1l, length(unique(adpc$PCSPEC)))
     expect_named(listings_1l, expected = as.character(unique(adpc$PCSPEC)))
-    
+
     # For 2 case
     listings_2l <- l_pkconc(adpc, listgroup_vars = c("PARAM", "PCSPEC", "ROUTE"),
                             grouping_vars = c("TRT01A", "USUBJID", "AVISIT"),
                             displaying_vars = c("NFRLT", "AFRLT", "AVAL"))
     expect_length(listings_2l, length(unique(interaction(adpc$PARAM, adpc$PCSPEC, adpc$ROUTE))))
-    expect_named(listings_2l, expected = as.character(unique(interaction(adpc$PARAM, adpc$PCSPEC, adpc$ROUTE))))
-    
+    expect_named(listings_2l, expected = as.character(
+      unique(
+        interaction(adpc$PARAM, adpc$PCSPEC, adpc$ROUTE)
+      )
+    )
+    )
+
     # For 4 case
     listings_4l <- l_pkconc(adpc, listgroup_vars = c("PARAM", "PCSPEC", "ROUTE", "USUBJID"),
                             grouping_vars = c("TRT01A", "USUBJID", "AVISIT"),
                             displaying_vars = c("NFRLT", "AFRLT", "AVAL"))
-    
+
     # Include lengths and names expected
-    expect_length(listings_4l, length(unique(interaction(adpc$PARAM, adpc$PCSPEC, adpc$ROUTE, adpc$USUBJID))))
-    expect_named(listings_4l, expected = as.character(interaction(adpc$PARAM, adpc$PCSPEC, adpc$ROUTE, adpc$USUBJID)))
-    
+    expect_length(listings_4l, length(unique(interaction(adpc$PARAM,
+                                                         adpc$PCSPEC,
+                                                         adpc$ROUTE,
+                                                         adpc$USUBJID))))
+    expect_named(listings_4l, expected = as.character(interaction(adpc$PARAM,
+                                                                  adpc$PCSPEC,
+                                                                  adpc$ROUTE,
+                                                                  adpc$USUBJID)))
+
     # All in correct format (list) and each internal element internally inherits listing_df
     expect_true(class(listings_1l) == "list" &&
-                  class(listings_2l) == "list" && 
+                  class(listings_2l) == "list" &&
                   class(listings_4l) == "list")
-    expect_true(all(sapply(listings_1l, inherits, "listing_df")) &&    
-                  all(sapply(listings_2l, inherits, "listing_df")) && 
+    expect_true(all(sapply(listings_1l, inherits, "listing_df")) &&
+                  all(sapply(listings_2l, inherits, "listing_df")) &&
                   all(sapply(listings_4l, inherits, "listing_df")))
   })
-  
+
   it("handles missing formatting_vars_table and uses a default built:", {
-    listings <- l_pkconc(adpc, 
+    listings <- l_pkconc(adpc,
                          listgroup_vars = c("PARAM", "PCSPEC", "ROUTE"),
                          grouping_vars = c("TRT01A", "USUBJID", "AVISIT"),
                          displaying_vars = c("NFRLT", "AFRLT", "AVAL"),
                          formatting_vars_table = NULL)
-    
+
     # Adds labels as column names & includes units when obvious and present  (i.e, AVALU for AVAL)
     expect_equal(var_labels(listings[[1]]),
                  expected = c(TRT01A = attr(adpc$TRT01A, "label"),
                               USUBJID = attr(adpc$USUBJID, "label"),
                               AVISIT = attr(adpc$AVISIT, "label"),
-                              NFRLT = attr(adpc$NFRLT, "label"), 
-                              AFRLT = attr(adpc$AFRLT, "label"), 
-                              AVAL = paste0(attr(adpc$AVAL, "label"), " (", unique(adpc$AVALU), ")"),
+                              NFRLT = attr(adpc$NFRLT, "label"),
+                              AFRLT = attr(adpc$AFRLT, "label"),
+                              AVAL = paste0(attr(adpc$AVAL, "label"),
+                                            " (", unique(adpc$AVALU), ")"),
                               AVALU = "AVALU"))
   })
-  
+
   it("handles missing subtitle_lists and creates a default", {
     listings <- l_pkconc(adpc, listgroup_vars = c("PARAM", "PCSPEC", "ROUTE"),
                          grouping_vars = c("TRT01A", "USUBJID", "AVISIT"),
                          displaying_vars = c("NFRLT", "AFRLT", "AVAL"),
                          subtitle_lists = NULL)
-    
+
     # Check if the subtitle is in the correct format
     expect_equal(attr(listings[[1]], "subtitles"),
                  expected = "Analyte: A\nSpecimen: Plasma\nAdministration: Oral")
-    
+
   })
-  
+
   it("handles missing footnote_table (no footnote)", {
     listings <- l_pkconc(adpc, listgroup_vars = c("PARAM", "PCSPEC", "ROUTE"),
                          grouping_vars = c("TRT01A", "USUBJID", "AVISIT"),
@@ -98,23 +110,23 @@ describe("l_pkconc", {
                          footnote_table = NULL)
     expect_equal(attr(listings[[1]], "main_footer"), expected =  character())
   })
-  
+
   it("handles empty data frame by providing empty list", {
-    
+
     # Define the input for the function
     empty_adpc <- adpc[0, ]
-    
+
     # Define the expected output
     empty_list <- list()
     names(empty_list) <- character()
-    
+
     # Check if the output is as expected
     expect_equal(l_pkconc(empty_adpc, listgroup_vars = c("PARAM", "PCSPEC", "ROUTE"),
                           grouping_vars = c("TRT01A", "USUBJID", "AVISIT"),
                           displaying_vars = c("NFRLT", "AFRLT", "AVAL")),
                  expected = empty_list)
   })
-  
+
   it("handles missing required columns", {
     incomplete_adpc <- adpc %>% select(-AFRLT)
     expect_error(l_pkconc(incomplete_adpc, listgroup_vars = c("PARAM", "PCSPEC", "ROUTE"),
@@ -122,7 +134,7 @@ describe("l_pkconc", {
                           displaying_vars = c("NFRLT", "AFRLT", "AVAL")),
                  "Missing required columns: AFRLT")
   })
-  
+
   it("handles non-unique units", {
     non_unique_units_adpc <- adpc
     non_unique_units_adpc$AVALU <- c("ng/mL", "ng/mL", "ng/L", "g/L")
@@ -131,7 +143,7 @@ describe("l_pkconc", {
                             displaying_vars = c("NFRLT", "AFRLT", "AVAL")),
                    "pkcl01, but not unique unit in ")
   })
-  
+
   it("handles custom formatting_vars_table", {
     custom_formatting_vars_table <- data.frame(
       var_name = c("TRT01A", "USUBJID", "AVISIT", "NFRLT", "AFRLT", "AVAL"),
@@ -144,12 +156,12 @@ describe("l_pkconc", {
       unit = c(NA, NA, NA, NA, NA, "AVALU"),
       stringsAsFactors = FALSE
     )
-    
+
     listings <- l_pkconc(adpc, listgroup_vars = c("PARAM", "PCSPEC", "ROUTE"),
                          grouping_vars = c("TRT01A", "USUBJID", "AVISIT"),
                          displaying_vars = c("NFRLT", "AFRLT", "AVAL"),
                          formatting_vars_table = custom_formatting_vars_table)
-    
+
     # Check if 0s, NAs, and units are formatted correctly
     expect_equal(as.vector(listings$`A.Plasma.Oral`$NFRLT), c("0", "1"))
     expect_equal(as.vector(listings$`A.Plasma.Oral`$AFRLT), c("0", "1.12"))
@@ -158,21 +170,23 @@ describe("l_pkconc", {
     expect_equal(as.vector(listings$`B.Plasma.IV`$AFRLT), c("0", "1.05"))
     expect_equal(as.vector(listings$`B.Plasma.IV`$AVAL), c("31", NA))
     expect_equal(attr(listings$`B.Plasma.IV`$AVAL, "format_na_str"), "missing")
-    
+
     # Check the structure of the listings
-    expect_equal(attr(listings$`A.Plasma.Oral`, "main_title"), 
-                 "Listing of PK Concentration by Treatment Group, Subject and Nominal Time, PK Population")
-    expect_equal(attr(listings$`A.Plasma.Oral`, "subtitles"), 
+    expect_equal(attr(listings$`A.Plasma.Oral`, "main_title"),
+                 paste0("Listing of PK Concentration by Treatment Group,",
+                        "Subject and Nominal Time, PK Population"))
+    expect_equal(attr(listings$`A.Plasma.Oral`, "subtitles"),
                  "Analyte: A\nSpecimen: Plasma\nAdministration: Oral")
-    expect_equal(attr(listings$`A.Plasma.Oral`, "main_footer"), 
+    expect_equal(attr(listings$`A.Plasma.Oral`, "main_footer"),
                  "*: Patients excluded from the summary table and mean plots")
-    expect_equal(attr(listings$`B.Plasma.IV`, "main_title"), 
-                 "Listing of PK Concentration by Treatment Group, Subject and Nominal Time, PK Population")
-    expect_equal(attr(listings$`B.Plasma.IV`, "subtitles"), 
+    expect_equal(attr(listings$`B.Plasma.IV`, "main_title"),
+                 paste0("Listing of PK Concentration by Treatment Group,",
+                        "Subject and Nominal Time, PK Population"))
+    expect_equal(attr(listings$`B.Plasma.IV`, "subtitles"),
                  "Analyte: B\nSpecimen: Plasma\nAdministration: IV")
-    expect_equal(attr(listings$`B.Plasma.IV`, "main_footer"), 
+    expect_equal(attr(listings$`B.Plasma.IV`, "main_footer"),
                  "*: Patients excluded from the summary table and mean plots")
-    
+
     # Check the attributes of the columns
     expect_equal(attr(listings$`A.Plasma.Oral`$TRT01A, "label"), "Actual treatment")
     expect_equal(attr(listings$`A.Plasma.Oral`$USUBJID, "label"), "Unique Subject ID")
@@ -181,7 +195,7 @@ describe("l_pkconc", {
     expect_equal(attr(listings$`A.Plasma.Oral`$AFRLT, "label"), "Actual time from first dose")
     expect_equal(attr(listings$`A.Plasma.Oral`$AVAL, "label"), "Analysis value (mg/L)")
     expect_equal(attr(listings$`A.Plasma.Oral`$AVALU, "label"), "AVALU")
-    
+
     expect_equal(attr(listings$`B.Plasma.IV`$TRT01A, "label"), "Actual treatment")
     expect_equal(attr(listings$`B.Plasma.IV`$USUBJID, "label"), "Unique Subject ID")
     expect_equal(attr(listings$`B.Plasma.IV`$AVISIT, "label"), "Actual visit")
@@ -189,6 +203,6 @@ describe("l_pkconc", {
     expect_equal(attr(listings$`B.Plasma.IV`$AFRLT, "label"), "Actual time from first dose")
     expect_equal(attr(listings$`B.Plasma.IV`$AVAL, "label"), "Analysis value (mg/L)")
     expect_equal(attr(listings$`B.Plasma.IV`$AVALU, "label"), "AVALU")
-    
+
   })
 })