static @Nullable PsiReferenceExpression createMockReference(PsiElement place, @NotNull PsiType qualifierType, LookupElement qualifierItem) {
    return createMockReference(place, qualifierType, qualifierItem, ".");
  }
static @Nullable PsiReferenceExpression createMockReference(PsiElement place, @NotNull PsiType qualifierType, LookupElement qualifierItem)