code: func (a *Agent) UpdateACLToken(token string, q *WriteOptions) (*WriteMeta, error) {
  	return a.updateToken("acl_token", token, q)
  }
docs: // UpdateACLToken updates the agent's "acl_token". See updateToken for more
  // details.
  //
  // DEPRECATED (ACL-Legacy-Compat) - Prefer UpdateDefaultACLToken for v1.4.3 and above