def user = ComponentAccessor.getJiraAuthenticationContext().getUser().getName()
MutableIssue updatedIssue = ComponentAccessor.getIssueManager().getIssueObject(currentIssue.getKey())
updatedIssue.setAssigneeId(user)
IssueManager issueManager = ComponentAccessor.getIssueManager();
issueManager.updateIssue(user, updatedIssue, EventDispatchOption.ISSUE_UPDATED, true)