diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/StudyUtils.java b/python/educational-core/student/src/com/jetbrains/edu/learning/StudyUtils.java index 69542b448629..020dbc27f58e 100644 --- a/python/educational-core/student/src/com/jetbrains/edu/learning/StudyUtils.java +++ b/python/educational-core/student/src/com/jetbrains/edu/learning/StudyUtils.java @@ -67,6 +67,7 @@ import java.awt.*; import java.io.*; import java.util.ArrayList; import java.util.Collection; +import java.util.Iterator; import java.util.List; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; @@ -115,7 +116,11 @@ public class StudyUtils { } public static T getFirst(@NotNull final Iterable container) { - return container.iterator().next(); + Iterator iterator = container.iterator(); + if (!iterator.hasNext()) { + return null; + } + return iterator.next(); } public static boolean indexIsValid(int index, @NotNull final Collection collection) {