code: def test_map(self, f):
      data = np.array(
          [
              ["E", "GHIJ", "HIJKLMNOP", "DEFGHIJ"],
              [
                  "CDE",
                  "ABCDEFGHIJKLMNOPQ",
                  "DEFGHIJKLMNOPQRS",
                  "ABCDEFGHIJK",
              ],
              ["DEFGHIJKLMNOPQR", "DEFGHI", "DEFGHIJ", "FGHIJK"],
              ["EFGHIJKLM", "EFGHIJKLMNOPQRS", "ABCDEFGHI", "DEFGHIJ"],
          ],
          dtype=object,
      )
      la = LabelArray(data, missing_value=None)
  
      numpy_transformed = np.vectorize(f)(data)
      la_transformed = la.map(f).as_string_array()
  
      assert_equal(numpy_transformed, la_transformed)
  
imports: from itertools import product
  from operator import eq, ne
  import warnings
  import numpy
  from toolz import take
  from zipline.lib.labelarray import LabelArray
  from zipline.testing import check_arrays, parameter_space, ZiplineTestCase
  from zipline.testing.predicates import assert_equal
  from zipline.utils.compat import unicode
label_desc: Use image node_id 4 for calling the LabelArrayTestCase obj's underlying member method code with example usage: obj.test_map(f) without return types