code: def test_slicing_preserves_attributes(self, slice_):
      arr = LabelArray(self.strs.reshape((9, 3)), missing_value="")
      sliced = arr[slice_]
      self.assertIsInstance(sliced, LabelArray)
      self.assertIs(sliced.categories, arr.categories)
      self.assertIs(sliced.reverse_categories, arr.reverse_categories)
      self.assertIs(sliced.missing_value, arr.missing_value)
  
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 9 for calling the LabelArrayTestCase obj's underlying member method code with example usage: obj.test_slicing_preserves_attributes(slice_) without return types