docs: public String selectCountByExample(MappedStatement ms) {
          Class<?> entityClass = getEntityClass(ms);
          StringBuilder sql = new StringBuilder("SELECT ");
          if (isCheckExampleEntityClass()) {
              sql.append(SqlHelper.exampleCheck(entityClass));
          }
          sql.append(SqlHelper.exampleCountColumn(entityClass));
          sql.append(SqlHelper.fromTable(entityClass, tableName(entityClass)));
          sql.append(SqlHelper.exampleWhereClause());
          sql.append(SqlHelper.exampleForUpdate());
          return sql.toString();
      }