docs: function MyLdapAuth(opts) {
    this.opts = opts;
    assert.ok(opts.url);
    assert.ok(opts.searchBase);
    assert.ok(opts.searchFilter);
  
    // optional option: tls_ca
  
    this.log = opts.log4js && opts.log4js.getLogger('ldapauth');
  
    var clientOpts = {url: opts.url};
    if (opts.log4js && opts.verbose) {
      clientOpts.log4js = opts.log4js;
    }
  }