code: def test_dataframe_dummies_all_obj(self, df, sparse):
      df = df[["A", "B"]]
      result = get_dummies(df, sparse=sparse)
      expected = DataFrame(
          {
              "A_a": [1, 0, 1],
              "A_b": [0, 1, 0],
              "B_b": [1, 1, 0],
              "B_c": [0, 0, 1],
          },
          dtype=bool,
      )
      if sparse:
          expected = DataFrame(
              {
                  "A_a": SparseArray([1, 0, 1], dtype="bool"),
                  "A_b": SparseArray([0, 1, 0], dtype="bool"),
                  "B_b": SparseArray([1, 1, 0], dtype="bool"),
                  "B_c": SparseArray([0, 0, 1], dtype="bool"),
              }
          )
  
      tm.assert_frame_equal(result, expected)
  
imports: import re
  import unicodedata
  import numpy
  import pytest
  import pandas.util._test_decorators
  from pandas.core.dtypes.common import is_integer_dtype
  import pandas
  from pandas import ArrowDtype, Categorical, CategoricalDtype, CategoricalIndex, DataFrame, Index, RangeIndex, Series, SparseDtype, get_dummies
  import pandas._testing
  from pandas.core.arrays.sparse import SparseArray
label_desc: Use image node_id 11 for calling the TestGetDummies obj's underlying member method code with example usage: obj.test_dataframe_dummies_all_obj(df, sparse) without return types