Method convert

app/src/main/java/androidx/paging/DataSource.java:199–206

(Function<List<A>, List<B>> function, List<A> source)

    }

    static <A, B> List<B> convert(Function<List<A>, List<B>> function, List<A> source) {
        List<B> dest = function.apply(source);
        if (dest.size() != source.size()) {
            throw new IllegalStateException("Invalid Function " + function
                    + " changed return size. This is not supported.");
        }
        return dest;
    }

    // Since we currently rely on implementation details of two implementations,
    // prevent external subclassing, except through exposed subclasses