code: def _check_dim(X):
      """
      Internal function to assert univariate data
      """
      if X.shape[1] != 1:
          raise ValueError(
              "MAD algorithm is just for univariate data. "
              "Got Data with {} Dimensions.".format(X.shape[1])
          )
  
file_path: pyod/pyod/models/mad.py
imports: from __future__ import division
  from __future__ import print_function
  import numpy
  from sklearn.utils import check_array
  from .base import BaseDetector
label_desc: Use image node_id 1 for calling a global function with example usage: _check_dim(X) without return types