/** Robots tag value indicating no indexing or following */
    private static final String ROBOTS_TAG_NONE = "none";

    /** Robots tag value indicating no indexing */
    private static final String ROBOTS_TAG_NOINDEX = "noindex";

    /** Robots tag value indicating no following of links */
    private static final String ROBOTS_TAG_NOFOLLOW = "nofollow";

  // operation in the constructor.
  //
  // 1. In the listener that performs the callback. In this case it is fine since inputFuture is
  //    assigned prior to calling addListener, and addListener happens-before any invocation of the
  //    listener. Notably, this means that 'volatile' is unnecessary to make 'inputFuture' visible
  //    to the listener.
  //

   * corresponding {@link Set} implementation (such as {@link java.util.HashMap} or {@link
   * java.util.TreeMap}).
   *
   * <p>Each method invocation on the set returned by this method results in exactly one method
   * invocation on the backing map or its {@code keySet} view, with one exception. The {@code
   * addAll} method is implemented as a sequence of {@code put} invocations on the backing map.
   *

# LDAP attribute for postal code.
ldap.attr.postalCode=postalCode
# LDAP attribute for physical delivery office name.
ldap.attr.physicalDeliveryOfficeName=physicalDeliveryOfficeName
# LDAP attribute for destination indicator.
ldap.attr.destinationIndicator=destinationIndicator
# LDAP attribute for international ISDN number.
ldap.attr.internationaliSDNNumber=internationaliSDNNumber
# LDAP attribute for state.
ldap.attr.state=st