docs: def glance(self, nitems=5):
          """Quick and partial glance of the data matrix.
  
          Parameters
          ----------
          nitems : int
              Number of items to glance from the dataset.
              Default : 5
  
          Returns
          -------
          dict
  
          """
          nitems = max([1, min([nitems, self.num_samples - 1])])
          return self.__take(nitems, iter(self.__data.items()))