class_docstr_tok: []
code: def _verify_ref_groups_dict_len(self, df, ref_groups_dict):
      if len(ref_groups_dict) != len(df["attribute_name"].unique()):
          raise ValueError
  
imports: import logging
  from aequitas.plotting import assemble_ref_groups
  import numpy
  import pandas
  from scipy import stats
label_desc: Use image node_id 4 for calling the Bias obj's underlying member method code with example usage: obj._verify_ref_groups_dict_len(df, ref_groups_dict) without return types