Used to mark a transaction to be well-formed. That means:

• tx is well-formed according to the Daml-LF definition, i.e., a root node is not child of another node and every non-root node has exactly one parent and is reachable from a root node. (No cycles, no sharing, no orphaned node).
• All node Ids are non-negative.
• The type parameter S determines whether all create nodes have suffixed IDs or none.
• Create nodes have unique contract ids of shape com.daml.lf.value.Value.ContractId.V1. The contract id of a create node is not referenced before the node. The contract id of a rolled back create node is not referenced outside its rollback scope.
• The discriminators of create nodes without suffixed contract ids are unique among all discriminators that appear in the transaction.
• Every action node has at least one signatory.
• Every signatory is also a stakeholder.
• Fetch actors are defined.
• All created contract instances and choice arguments in the transaction can be serialized.
• All nodes in the transaction have the optLocation field set to None.
• metadata contains seeds exactly for those node IDs from tx that should have a seed (creates and exercises).
• Keys of transaction nodes don't contain contract IDs.
• The maintainers of keys are non-empty.
• ByKey nodes have a key.
• All parties referenced by the transaction can be converted to com.digitalasset.canton.topology.PartyId
• The transaction has the optUsedPackages set to scala.None$
• Every rollback node has at least one child and no rollback node appears at the root unless the transaction has been merged by Canton.