code: public <T> T createInstance(DatastoreType datastoreType, DynamicType<?> types) {
          return newInstance(getDatastoreId(datastoreType), datastoreType, types, TransactionalCache.Mode.WRITE);
      }
docs: Return the proxy instance which corresponds to the given datastore type for
  writing.
  
  @param datastoreType
  The datastore type.
  @param types
  The {@link DynamicType}.
  @param <T>
  The instance type.
  @return The instance.