* CheckDefaultStorageClass checks if a default storage class is defined.

* CheckNodesReady checks if all nodes are ready.

* CheckRBAC checks if the user has the necessary privileges allow * Acorn to run.

IsFailed is a simple helper function marking a list of check results as failed if one or more results show failed status.

PostInstallChecks is a list of all checks that are run after the installation.

PreInstallChecks is a list of all checks that are run before the installation.

RunChecks runs a list of checks and returns their results as a list.

CheckOptions defines some extra settings for the tests.

CheckResult describes the results of a check, making it human-readable.