code: public static Optional<SoyRuntimeType> getUnboxedType(SoyType soyType) {
      // Optional is immutable so Optional<Subclass> can always be safely cast to Optional<SuperClass>
      @SuppressWarnings({"unchecked", "rawtypes"})
      Optional<SoyRuntimeType> typed = (Optional) primitiveTypeCache.getUnchecked(soyType);
      return typed;
    }
docs: Returns the unboxed {@code jbcsrc} representation of the given type, or absent if no such
  representation exists.
  
  <p>Types will fail to have unboxed representations mostly for unknown, any and union types.