docs: function normalize(args) {
    let result = {
      queries:  null,
      callback: null
    };
  
    if (args.length === 1 && Array.isArray(args[0])) {
      result.queries = args[0];
    } else if (args.length === 2 && Array.isArray(args[0])) {
      result.queries = args[0];
  
      if (typeof args[1] === 'function') {
        result.callback = args[1];
      }
    } else {
      result.queries = args;
  
      if (typeof result.queries[result.queries.length - 1] === 'function') {
        result.callback = result.queries.pop();
      }
    }
  
    return result;
  }