class_docstr_tok: []
code: def _verify_ref_group_loc(self, group_slice):
      if len(group_slice) < 1:
          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 5 for calling the Bias obj's underlying member method code with example usage: obj._verify_ref_group_loc(group_slice) without return types