imageVersion property

The version of software inside the cluster.

It must be one of the supported Dataproc Versions (https://cloud.google.com/dataproc/docs/concepts/versioning/dataproc-versions#supported_dataproc_versions), such as "1.2" (including a subminor version, such as "1.2.29"), or the "preview" version (https://cloud.google.com/dataproc/docs/concepts/versioning/dataproc-versions#other_versions). If unspecified, it defaults to the latest Debian version.

Optional.