'Returns an instance of Model class by ID.
This is really just a shorthand for Key(cls, id, ...).get().
Args:
id: A string or integer key ID.
parent: Optional parent key of the model to get.
namespace: Optional namespace.
app: Optional app ID.
**ctx_options: Context options.
Returns:
A model instance or None if not found.'

@classmethod
@utils.positional(3)
def _get_by_id(cls, id, parent=None, **ctx_options):

    return cls._get_by_id_async(id, parent=parent, **ctx_options).get_result()
