docstr: This test is really slow so we don't want it run by default.
          
docstr_tok: ["This","test","is","really","slow","so","we","do","n't","want","it","run","by","default","."]
code: def manual_narrow_condense_back_to_valid_size_slow(self):
      """This test is really slow so we don't want it run by default."""
      # tests that we don't try to create an 'int24' (which is meaningless)
      categories = self.create_categories(24, plus_one=False)
      categories.append(categories[0])
      arr = LabelArray(categories, missing_value=categories[0])
      assert_equal(arr.itemsize, 4)
      self.check_roundtrip(arr)
  
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 21 for calling the LabelArrayTestCase obj's underlying member method code with example usage: obj.manual_narrow_condense_back_to_valid_size_slow() without return types