public void setReferral(String referral) {
        setEnvironmentProperty(Context.REFERRAL, referral);
    }
Sets the LDAP referral behavior when creating a connection.  Defaults to {@code follow}.  See the Sun/Oracle LDAP
<a href="http://java.sun.com/products/jndi/tutorial/ldap/referral/jndi.html">referral documentation</a> for more.

@param referral the referral property.
@see <a href="http://java.sun.com/products/jndi/tutorial/ldap/referral/jndi.html">Referrals in JNDI</a>
core/src/main/java/org/apache/shiro/realm/ldap/JndiLdapContextFactory.java