public String calcGenerics(@NotNull PsiElement context, InsertionContext insertionContext) {
    if (insertionContext.getCompletionChar() == '<') {
      return "";
    }

    assert context.isValid();
    if (myDiamond) {
      return "<>";
    }

    if (getObject() instanceof PsiClass) {
      PsiClass psiClass = (PsiClass) getObject();
      PsiResolveHelper resolveHelper =
          JavaPsiFacade.getInstance(psiClass.getProject()).getResolveHelper();
      PsiSubstitutor substitutor = getSubstitutor();
      StringBuilder builder = new StringBuilder();
      for (PsiTypeParameter parameter : psiClass.getTypeParameters()) {
        PsiType substitute = substitutor.substitute(parameter);
        if (substitute == null
            || (PsiUtil.resolveClassInType(substitute) == parameter
                && resolveHelper.resolveReferencedClass(parameter.getName(), context)
                    != CompletionUtil.getOriginalOrSelf(parameter))) {
          return "";
        }
        if (builder.length() > 0) {
          builder.append(", ");
        }
        builder.append(substitute.getCanonicalText());
      }
      if (builder.length() > 0) {
        return "<" + builder + ">";
      }
    }
    return "";
  }
  private static boolean shouldMarkRed(@NotNull Object object, @NotNull PsiElement place) {
    if (!(object instanceof PsiMember)) return false;
    if (Java15APIUsageInspectionBase.isForbiddenApiUsage(
        (PsiMember) object, PsiUtil.getLanguageLevel(place))) return true;

    if (object instanceof PsiEnumConstant) {
      return findConstantsUsedInSwitch(place)
          .contains(CompletionUtil.getOriginalOrSelf((PsiEnumConstant) object));
    }
    return false;
  }
  private static boolean shouldMarkRed(@NotNull Object object, @NotNull PsiElement place) {
    if (!(object instanceof PsiMember)) return false;
    if (Java15APIUsageInspectionBase.isForbiddenApiUsage(
        (PsiMember) object, PsiUtil.getLanguageLevel(place))) return true;

    if (object instanceof PsiEnumConstant) {
      return findConstantsUsedInSwitch(place)
          .contains(CompletionUtil.getOriginalOrSelf((PsiEnumConstant) object));
    }
    if (object instanceof PsiClass
        && ReferenceListWeigher.INSTANCE.getApplicability((PsiClass) object, place)
            == inapplicable) {
      return true;
    }
    return false;
  }
  private boolean shouldQualify(PsiField field, InsertionContext context) {
    if (myHelper != null && !myHelper.willBeImported()) {
      return true;
    }

    if (getAttribute(FORCE_QUALIFY) != null) {
      return true;
    }

    PsiReference reference = context.getFile().findReferenceAt(context.getStartOffset());
    if (reference instanceof PsiReferenceExpression
        && !((PsiReferenceExpression) reference).isQualified()) {
      final PsiVariable target =
          JavaPsiFacade.getInstance(context.getProject())
              .getResolveHelper()
              .resolveReferencedVariable(field.getName(), (PsiElement) reference);
      return !field
          .getManager()
          .areElementsEquivalent(target, CompletionUtil.getOriginalOrSelf(field));
    }
    return false;
  }
 @NotNull
 public static Set<PsiField> findConstantsUsedInSwitch(@Nullable PsiElement position) {
   if (IN_SWITCH_LABEL.accepts(position)) {
     Set<PsiField> used = ContainerUtil.newLinkedHashSet();
     PsiSwitchStatement sw = PsiTreeUtil.getParentOfType(position, PsiSwitchStatement.class);
     assert sw != null;
     final PsiCodeBlock body = sw.getBody();
     assert body != null;
     for (PsiStatement statement : body.getStatements()) {
       if (statement instanceof PsiSwitchLabelStatement) {
         final PsiExpression value = ((PsiSwitchLabelStatement) statement).getCaseValue();
         if (value instanceof PsiReferenceExpression) {
           final PsiElement target = ((PsiReferenceExpression) value).resolve();
           if (target instanceof PsiField) {
             used.add(CompletionUtil.getOriginalOrSelf((PsiField) target));
           }
         }
       }
     }
     return used;
   }
   return Collections.emptySet();
 }
  public static Set<LookupElement> processJavaReference(
      PsiElement element,
      PsiJavaReference javaReference,
      ElementFilter elementFilter,
      JavaCompletionProcessor.Options options,
      final PrefixMatcher matcher,
      CompletionParameters parameters) {
    final Set<LookupElement> set = new LinkedHashSet<LookupElement>();
    final Condition<String> nameCondition =
        new Condition<String>() {
          @Override
          public boolean value(String s) {
            return matcher.prefixMatches(s);
          }
        };

    PsiMethodCallExpression call =
        PsiTreeUtil.getParentOfType(element, PsiMethodCallExpression.class);
    boolean checkInitialized =
        parameters.getInvocationCount() <= 1
            && call != null
            && PsiKeyword.SUPER.equals(call.getMethodExpression().getText());

    final JavaCompletionProcessor processor =
        new JavaCompletionProcessor(
            element, elementFilter, options.withInitialized(checkInitialized), nameCondition);
    final PsiType plainQualifier = processor.getQualifierType();
    PsiType qualifierType = plainQualifier;

    PsiType runtimeQualifier = getQualifierCastType(javaReference, parameters);
    if (runtimeQualifier != null) {
      PsiType composite =
          qualifierType == null
              ? runtimeQualifier
              : PsiIntersectionType.createIntersection(qualifierType, runtimeQualifier);
      PsiElement ctx = createContextWithXxxVariable(element, composite);
      javaReference =
          (PsiReferenceExpression)
              JavaPsiFacade.getElementFactory(element.getProject())
                  .createExpressionFromText("xxx.xxx", ctx);
      qualifierType = runtimeQualifier;
      processor.setQualifierType(qualifierType);
    }

    javaReference.processVariants(processor);

    final PsiTypeLookupItem castItem =
        runtimeQualifier == null
            ? null
            : PsiTypeLookupItem.createLookupItem(
                runtimeQualifier, (PsiReferenceExpression) javaReference);

    final boolean pkgContext = inSomePackage(element);

    final Set<PsiMember> mentioned = new THashSet<PsiMember>();
    for (CompletionElement completionElement : processor.getResults()) {
      for (LookupElement item : createLookupElements(completionElement, javaReference)) {
        item.putUserData(QUALIFIER_TYPE_ATTR, qualifierType);
        final Object o = item.getObject();
        if (o instanceof PsiClass && !isSourceLevelAccessible(element, (PsiClass) o, pkgContext)) {
          continue;
        }
        if (o instanceof PsiMember) {
          if (isInExcludedPackage((PsiMember) o, true)) {
            continue;
          }
          mentioned.add(CompletionUtil.getOriginalOrSelf((PsiMember) o));
        }
        set.add(
            highlightIfNeeded(
                qualifierType,
                castQualifier(item, castItem, plainQualifier, processor),
                o,
                element));
      }
    }

    if (javaReference instanceof PsiJavaCodeReferenceElement
        && !((PsiJavaCodeReferenceElement) javaReference).isQualified()) {
      final StaticMemberProcessor memberProcessor = new JavaStaticMemberProcessor(parameters);
      memberProcessor.processMembersOfRegisteredClasses(
          matcher,
          new PairConsumer<PsiMember, PsiClass>() {
            @Override
            public void consume(PsiMember member, PsiClass psiClass) {
              if (!mentioned.contains(member)
                  && processor.satisfies(member, ResolveState.initial())) {
                set.add(memberProcessor.createLookupElement(member, psiClass, true));
              }
            }
          });
    }

    return set;
  }