shortenClassReferences does not "shorten" java.util.Collections

Hello.

I am writing an intention that is adding some statements, these statements uses types from external library and some from the JDK (such as `java.util.Collections`). The types from the external libraries are imported correctly, but the types coming from the JDK are not.

At some point the intention adds this statement

var stmt = JavaPsiFacade.getElementFactory(project).createStatementFromText("foo.bar(java.util.Collections.singleton(\"\"))", null)

Then the invoke method of the intention terminates with these lines on the `PsiCodeBlock` that received the statements :

var javaStyleManager = JavaCodeStyleManager.getInstance(project);
var formatter = CodeStyleManager.getInstance(project);

javaStyleManager.shortenClassReferences(formatter.reformat(catchBlock));

The test is written this way : 

public void testCatch() {
    myFixture.configureByFile("before" + name + ".java");

    assertTrue(action.isAvailable(getProject(), getEditor(), getFile()));
    myFixture.launchAction(action);
    myFixture.checkResultByFile("after" + name + ".java");
}

@Override
protected @NotNull LightProjectDescriptor getProjectDescriptor() {
    return new DefaultLightProjectDescriptor() {
        @Override
        public void configureModule(@NotNull Module module, @NotNull ModifiableRootModel model, @NotNull ContentEntry contentEntry) {
            super.configureModule(module, model, contentEntry);
                String jarPath = new File("src/test/testData/jars").getAbsolutePath();
                PsiTestUtil.addLibrary(
                        model,
                        "libExt",
                        jarPath,
                        "libA.jar",
                        "libB.jar");
        }
    };
}

The test extends `LightJavaCodeInsightFixtureTestCase`.

The test fails because `java.util.Collections` does not appear in the imports. I have searched on this forum similar problem. The only thing that seemed to work is a comment from Yann Cebron .

If the fixture in the test is configured with 

myFixture.addClass("package java.util; public class Collections {}");

The intention correctly add the imports of `java.util.Collections`.

While this work, I wonder if I didn't miss something in the test setup, maybe around the `LightProjectDescriptor`. Thanks in advance for your support.