public SearchResponse executeSearchOperation(
        final String baseDn,
        final FilterTemplate filter,
        final int pageSize,
        final String... returnAttributes) throws LdapException {
        return executeSearchOperation(baseDn, filter, pageSize, null, returnAttributes);
    }
Execute search operation.

@param baseDn           the base dn
@param filter           the filter
@param pageSize         the page size
@param returnAttributes the return attributes
@return the response
@throws LdapException the ldap exception
support/cas-server-support-ldap-core/src/main/java/org/apereo/cas/util/LdapConnectionFactory.java