[multiple] Cleanup: use LinkedHashSet.getFirst()

GitOrigin-RevId: ac2d373834829e3a33528afbeacee8037a935ead

java/java-impl/src/com/intellij/codeInsight/daemon/impl/quickfix/PullAsAbstractUpFix.java

@@ -157,7 +157,7 @@ public class PullAsAbstractUpFix extends LocalQuickFixAndIntentionActionOnPsiEle
         name = JavaBundle.message("intention.name.extract.method.to.new.interface", methodWithOverrides.getName());
         canBePulledUp = false;
       } else if (classesToPullUp.size() == 1) {
-        final PsiClass baseClass = classesToPullUp.iterator().next();
+        final PsiClass baseClass = classesToPullUp.getFirst();
         name = JavaBundle.message("intention.name.pull.method.up.and.make.it.abstract.conditionally", methodWithOverrides.getName(), baseClass.getName(), !baseClass.hasModifierProperty(PsiModifier.ABSTRACT) ? 0 : 1);
       }
     }

java/java-impl/src/com/intellij/codeInsight/intention/impl/TypeExpression.java

@@ -45,7 +45,7 @@ public class TypeExpression extends Expression {
     }
     if (myItems.isEmpty()) return null;
 
-    final PsiType type = myItems.iterator().next().getType();
+    final PsiType type = myItems.getFirst().getType();
     return type == null ? null : new PsiTypeResult(type, project) {
       @Override
       public void handleRecalc(PsiFile psiFile, Document document, int segmentStart, int segmentEnd) {

platform/dvcs-impl/src/com/intellij/dvcs/push/ui/PushLog.java

@@ -497,7 +497,7 @@ public final class PushLog extends JPanel implements Disposable, UiDataProvider
       .toCollection(LinkedHashSet::new);
     if (checkedNodes.isEmpty()) return;
     // use new state from first lead node;
-    boolean newState = !checkedNodes.iterator().next().isChecked();
+    boolean newState = !checkedNodes.getFirst().isChecked();
     checkedNodes.forEach(n -> myTree.setNodeState(n, newState));
   }
 

platform/lang-impl/src/com/intellij/codeInspection/actions/RunInspectionIntention.java

@@ -117,7 +117,7 @@ public final class RunInspectionIntention implements IntentionAction, HighPriori
     LinkedHashSet<InspectionToolWrapper<?, ?>> allWrappers = new LinkedHashSet<>();
     allWrappers.add(toolWrapper);
     rootProfile.collectDependentInspections(toolWrapper, allWrappers, project);
-    List<InspectionToolWrapper<?, ?>> toolWrappers = allWrappers.size() == 1 ? Collections.singletonList(allWrappers.iterator().next()) : new ArrayList<>(allWrappers);
+    List<InspectionToolWrapper<?, ?>> toolWrappers = allWrappers.size() == 1 ? Collections.singletonList(allWrappers.getFirst()) : new ArrayList<>(allWrappers);
     InspectionProfileImpl model = new InspectionProfileImpl(toolWrapper.getDisplayName(), new InspectionToolsSupplier.Simple(toolWrappers), rootProfile);
     for (InspectionToolWrapper wrapper : toolWrappers) {
       model.enableTool(wrapper.getShortName(), project);

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/actions/AttachToProcessActionBase.java

@@ -300,7 +300,7 @@ public abstract class AttachToProcessActionBase extends AnAction implements Dumb
     hostRecentItems.add(newRecentItem);
 
     while (hostRecentItems.size() > 4) {
-      hostRecentItems.remove(hostRecentItems.iterator().next());
+      hostRecentItems.remove(hostRecentItems.getFirst());
     }
   }
 

plugins/copyright/src/com/maddyhome/idea/copyright/psi/UpdatePsiFileCopyright.java

@@ -137,10 +137,10 @@ public abstract class UpdatePsiFileCopyright extends AbstractUpdateCopyright {
       }
 
       if (commentHere && found.size() == 1) {
-        CommentRange range = found.iterator().next();
+        CommentRange range = found.getFirst();
         // Is the comment in the right place?
-        if (langOpts.isRelativeBefore() && range.getFirst() == comments.get(0) ||
-            !langOpts.isRelativeBefore() && range.getLast() == comments.get(comments.size() - 1)) {
+        if (langOpts.isRelativeBefore() && range.getFirst() == comments.getFirst() ||
+            !langOpts.isRelativeBefore() && range.getLast() == comments.getLast()) {
           // Check to see if current copyright comment matches new one.
           String newComment = getCommentText("", "");
           resetCommentText();

plugins/junit/src/com/intellij/execution/junit/JUnitConfiguration.java

@@ -838,7 +838,7 @@ public class JUnitConfiguration extends JavaTestConfigurationWithDiscoverySuppor
       if (TEST_PATTERN.equals(TEST_OBJECT)) {
         final int size = myPattern.size();
         if (size == 0) return JUnitBundle.message("default.junit.config.name.temp.suite");
-        String fqName = myPattern.iterator().next();
+        String fqName = myPattern.getFirst();
         String firstName =
           fqName.contains("*") ? fqName
                                : StringUtil.getShortName(fqName.contains("(") ? StringUtil.getPackageName(fqName, '(') : fqName);