code: def fit(self, X):
          
          X = column_or_1d(X, warn=True)
          _check_numpy_unicode_bug(X)
          self.classes_ = np.unique(X)
          return self
docs: Fit label encoder
  
          Parameters
          ----------
          y : array-like of shape (n_samples,)
              Target values.
  
          Returns
          -------
          self : returns an instance of self.