OneOf.java

// Test case for Issue 979:
// https://github.com/typetools/checker-framework/issues/979

// @below-java8-jdk-skip-test

import java.util.List;

@SuppressWarnings("nullness") // don't bother with implementations
class OneOf {
    static List<String> alist;

    static <V> V oneof(V v1, V v2) {
        return v1;
    }

    static <T> List<T> empty() {
        return null;
    }
}

class OneOfUse {
    List<String> foo() {
        return OneOf.oneof(OneOf.alist, OneOf.empty());
    }
}