code: function isArrayOfArray(o) {
      if(isArray(o)) {
        if(o.length > 0) {
          if(isArray(o[0])) {
            return true;
          }
        }
      }
      return false;
    }
docs: Checks if an object is an array of arrays.
  @param {*} o Object.
  @returns {Boolean} A boolean to indicate if the object is array of arrays.