class_docstr: Base class for testing expected errors for pattern mining.
class_docstr_tok: ["Base","class","for","testing","expected","errors","for","pattern","mining","."]
code: def test_itemsets_type(self):
      # This is default behavior
      res_colindice = self.fpalgo(self.df, use_colnames=False)
      for i in res_colindice["itemsets"]:
          assert isinstance(i, frozenset) is True
  
      res_colnames = self.fpalgo(self.df, use_colnames=True)
      for i in res_colnames["itemsets"]:
          assert isinstance(i, frozenset) is True
  
imports: import sys
  from contextlib import contextmanager
  from io import StringIO
  import numpy
  import pandas
  from numpy.testing import assert_array_equal
  from packaging.version import Version
  from pandas import __version__
  from scipy.sparse import csr_matrix
  from mlxtend.preprocessing import TransactionEncoder
  from mlxtend.utils import assert_raises
label_desc: Use image node_id 2 for calling the FPTestErrors obj's underlying member method code with example usage: obj.test_itemsets_type() without return types