Returns an immutable instance of [PlaygroundExperimentBatchParams].
public PlaygroundExperimentBatchParams build()Returns an immutable instance of [PlaygroundExperimentBatchParams]. Further updates to this [Builder] will not mutate the returned instance. The following fields are required:
.datasetId()
.manifest()
.options()
.projectName()
.secrets()
IllegalStateException: if any required field is unset.