public String getReferral() {
        return (String) getEnvironmentProperty(Context.REFERRAL);
    }
Returns 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.

@return the LDAP referral behavior when creating a connection.
@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