Duplicate uassert & fassert codes

            uassert(

                28528,

                str::stream() << "Argument to listIndexes must be of type String, not "

                              << typeName(first.type()),

                first.type() == String);

            const NamespaceString ns(parseNs(dbname, cmdObj));

            uassert(

                28529,

                str::stream() << "Argument to listIndexes must be a collection name, "

                              << "not the empty string",

                !ns.coll().empty());

        else if (status != ErrorCodes::NoSuchKey) {

            // NoSuchKey means we have no $voter-tagged nodes in this config;

            // other errors are unexpected.

            fassert(28528, status);

        }

        // $stepDownCheck: one electable node plus ourselves

        pattern = _tagConfig.makePattern();

        status = _tagConfig.addTagCountConstraintToPattern(&pattern,

                                                           MemberConfig::kInternalElectableTagName,

                                                           2);

        if (status.isOK()) {

            _customWriteConcernModes[kStepDownCheckWriteConcernModeName] = pattern;

        }

        else if (status != ErrorCodes::NoSuchKey) {

            // NoSuchKey means we have no $electable-tagged nodes in this config;

            // other errors are unexpected

            fassert(28529, status);

        }