class_docstr: Tests for reshaping and concatenation.
class_docstr_tok: ["Tests","for","reshaping","and","concatenation","."]
code: def test_concat_with_reindex(self, data):
      # GH-33027
      a = pd.DataFrame({"a": data[:5]})
      b = pd.DataFrame({"b": data[:5]})
      result = pd.concat([a, b], ignore_index=True)
      expected = pd.DataFrame(
          {
              "a": data.take(
                  list(range(5)) + ([-1] * 5), allow_fill=True
              ),
              "b": data.take(
                  ([-1] * 5) + list(range(5)), allow_fill=True
              ),
          }
      )
      tm.assert_frame_equal(result, expected)
  
imports: import itertools
  import numpy
  import pytest
  import pandas
  import pandas._testing
  from pandas.api.extensions import ExtensionArray
  from pandas.core.internals.blocks import EABackedBlock
label_desc: Use image node_id 6 for calling the BaseReshapingTests obj's underlying member method code with example usage: obj.test_concat_with_reindex(data) without return types