ContainsClock returns true if the `rhs` clock is contained within the `lhs`, meaning that all `rhs` journals are present in `lhs` with an equal or greater offset.

FetchDocuments fetches the documents contained in journals matching the given selector, within the offset ranges bounded by |from| and |to|.

Initialize fetches existing collection offsets from the cluster, models each as a completed ingestion, and ensures all downstream data-flows have completed.

MaxClock reduces by taking the largest offset of each common journal.

MinClock reduces by taking the smallest offset of each common journal.

NewClusterDriver builds a ClusterDriver from the provided cluster clients, schemas, and collections.

NewGraph constructs a new *Graph.

RunTestCase runs a test case using the given Graph and Driver.

ErrAdvanceDisabled is a specific error returned when clock advance is called when advance is disabled.

ClusterDriver implements a Driver which drives actions against a data plane.

FailedVerify is details of a failed test verification.

Graph maintains the data-flow status of a running catalog.

PendingStat is a CatalogTask's read of its source which may not have happened yet.

Driver executes test actions.

TaskName is a type wrapper of a CatalogTask.Name() (which is itself a pf.Capture, pf.Collection (derivation), or pf.Materialization).

TestTime is an effective test time-point, in seconds.