private static void findTypeParameterExternalUsages( final PsiTypeParameter typeParameter, final Collection<UsageInfo> usages) { PsiTypeParameterListOwner owner = typeParameter.getOwner(); if (owner != null) { final PsiTypeParameterList parameterList = owner.getTypeParameterList(); if (parameterList != null) { final int paramsCount = parameterList.getTypeParameters().length; final int index = parameterList.getTypeParameterIndex(typeParameter); ReferencesSearch.search(owner) .forEach( reference -> { if (reference instanceof PsiJavaCodeReferenceElement) { final PsiReferenceParameterList parameterList1 = ((PsiJavaCodeReferenceElement) reference).getParameterList(); if (parameterList1 != null) { PsiTypeElement[] typeArgs = parameterList1.getTypeParameterElements(); if (typeArgs.length > index) { if (typeArgs.length == 1 && paramsCount > 1 && typeArgs[0].getType() instanceof PsiDiamondType) return true; usages.add( new SafeDeleteReferenceJavaDeleteUsageInfo( typeArgs[index], typeParameter, true)); } } } return true; }); } } }