operations on the type parameter are unchecked, it hides unsafe casts at invocations of the method, and it interacts badly with method overload

Question

What I am trying to achieve:

I have this piece of code I would like to improve:

As part of a Spring project (but this is really not a Spring question)

I have a straightforward piece of code that looks like this:

    private String transform(String input) {
        Function<String, String> transform = functionCatalog.lookup("theVeryComplexFunction");
        String output = transform.apply(input);

I test coverage on the "theVeryComplexFunction" method. With that said, in my code, I would like to make available some dummies, such as:

FunctionCatalog functionCatalog = new FunctionCatalog() {
            @Override
            public <T> T lookup(Class<?> type, String functionDefinition, String... expectedOutputMimeTypes) {
                return (T) (Function<String, String>) s -> "dummy";
            }

            @Override
            public Set<String> getNames(Class<?> type) {
                return null;
            }
        };

When running couple of static analysis, I am always getting:

[TypeParameterUnusedInFormals] Declaring a type parameter that is only used in the return type is a misuse of generics: operations on the type parameter are unchecked, it hides unsafe casts at invocations of the method, and it interacts badly with method overload resolution.

What I tried:

I tried removing the cast, unfortunately, it seems not to be the right direction.

Question:

How to declare this method, and be able to fix this scan result?