Moved from GitHub pydgraph/34
Posted by danielmai:
The preds field was added in Dgraph v1.0.8. It tracks the predicates mutated in a transaction and is handled by the client similar to the keys field by merging in the new list with the existing one per transaction.
Corresponding Go client change: Add a Preds field in TxnContext to allow Zero to abort transactions d… · dgraph-io/dgo@ed3c52b · GitHub