/**
  * sets the required constraints on the target certificate or attribute certificate. the
  * constraints are specified as an instance of <code>selector</code>. if <code>null</code>, no
  * constraints are defined.
  *
  * <p>the target certificate in a pkix path may be a certificate or an attribute certificate.
  *
  * <p>note that the <code>selector</code> specified is cloned to protect against subsequent
  * modifications.
  *
  * @param selector a <code>selector</code> specifying the constraints on the target certificate or
  *     attribute certificate (or <code>null</code>)
  * @see #gettargetconstraints
  * @see x509certstoreselector
  * @see x509attributecertstoreselector
  */
 public void settargetconstraints(selector selector) {
   if (selector != null) {
     this.selector = (selector) selector.clone();
   } else {
     this.selector = null;
   }
 }
 /**
  * returns the required constraints on the target certificate or attribute certificate. the
  * constraints are returned as an instance of <code>selector</code>. if <code>null</code>, no
  * constraints are defined.
  *
  * <p>the target certificate in a pkix path may be a certificate or an attribute certificate.
  *
  * <p>note that the <code>selector</code> returned is cloned to protect against subsequent
  * modifications.
  *
  * @return a <code>selector</code> specifying the constraints on the target certificate or
  *     attribute certificate (or <code>null</code>)
  * @see #settargetconstraints
  * @see x509certstoreselector
  * @see x509attributecertstoreselector
  */
 public selector gettargetconstraints() {
   if (selector != null) {
     return (selector) selector.clone();
   } else {
     return null;
   }
 }