@Nullable
    @SuppressWarnings("NullAway") // See inline comment.
    public E get(long key) {
        // We pass null as the default to a function which isn't explicitly annotated as nullable.
        // Not marking the function as nullable should allow us to eventually propagate the generic
        // parameter's nullability to the caller. If we were to mark it as nullable now, we would
        // also be forced to mark the return type of that method as nullable which harms the case
        // where you are passing in a non-null default value.
        return get(key, null);
    }
Gets the Object mapped from the specified key, or <code>null</code>
if no such mapping has been made.
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/util/collection/LongSparseArray.java