import com.atlassian.jira.component.ComponentAccessor
import org.apache.log4j.Level
import org.apache.log4j.Logger

log = Logger.getLogger("com.onresolve.confluence.groovy")
log.setLevel(Level.DEBUG)

def issue = "QQ-204"
def workflow = ComponentAccessor.getWorkflowManager().getWorkflow(issue).getDisplayName()
log.debug(workflow)

2019-12-09 17:00:11,540 ERROR [common.UserScriptEndpoint]: Script console script failed:
java.lang.NullPointerException: Cannot invoke method getDisplayName() on null object
	at Script485.run(Script485.groovy:9)