@VisibleForTesting
    Optional<WorkflowDef> lookupWorkflowDefinition(String workflowName, int workflowVersion) {
        Utils.checkArgument(
                StringUtils.isNotBlank(workflowName),
                "Workflow name must be specified when searching for a definition");
        return metadataDAO.getWorkflowDef(workflowName, workflowVersion);
    }
Populates metadata definitions within workflow objects. Benefits of loading and populating
metadata definitions upfront could be:

<ul>
  <li>Immutable definitions within a workflow execution with the added benefit of guaranteeing
      consistency at runtime.
  <li>Stress is reduced on the storage layer
</ul>
core/src/main/java/com/netflix/conductor/core/metadata/MetadataMapperService.java