They will be returned sorted by key, and the iterator
will fill in NULL for all values if specified.
@param read_op operation to add this action to
@param start_after list keys starting after start_after
@param max_return list no more than max_return keys
@param iter where to store the iterator
@param prval where to store the return value from this action
Start iterating over keys on an object.
They will be returned sorted by key, and the iterator will fill in NULL for all values if specified.
@param read_op operation to add this action to @param start_after list keys starting after start_after @param max_return list no more than max_return keys @param iter where to store the iterator @param prval where to store the return value from this action