code: def get(package_str, classname):
      '''Retrieve from the internal cache a class instance. All arguments are case-insensitive''' 
      if (package_str in _dynamo_cache) and (classname in _dynamo_cache[package_str]):
          return _dynamo_cache[package_str][classname]
      return Nonf get(package_str, classname):
      '''Retrieve from the internal cache a class instance. All arguments are case-insensitive''' 
      if (package_str in _dynamo_cache) and (classname in _dynamo_cache[package_str]):
          return _dynamo_cache[package_str][classname]
      return None
docs: Retrieve from the internal cache a class instance. All arguments are case-insensitive