added empty collection checks

Author: SergeyRuzin

src/Behavioral.Automation/Services/PrintValuesHelper.cs

@@ -1,15 +1,21 @@
 using System.Collections.Generic;
 using System.Linq;
 using Behavioral.Automation.Elements;
+using JetBrains.Annotations;
 
 namespace Behavioral.Automation.Services
 {
     public static class PrintValuesHelper
     {
-        public static string GetPrintableValues(this IEnumerable<ITableRowWrapper> rows)
+        public static string GetPrintableValues([NotNull] this IEnumerable<ITableRowWrapper> rows)
         {
-            var values = rows.Aggregate("\r\n|", (current, row) => current + (row.CellsText.Aggregate((x, y) => $" {x} | {y}") + " |\r\n |"));
-            return values.Remove(values.Length - 3);
+            if (rows.Any())
+            {
+                var values = rows.Aggregate("\r\n|", (current, row) => current + (row.CellsText.Aggregate((x, y) => $" {x} | {y}") + " |\r\n |"));
+                return values.Remove(values.Length - 3);
+            }
+
+            return "\r\n Rows collection was empty";
         }
     }
 }