code: def create_categories(width, plus_one):
      length = int(width / 8) + plus_one
      return [
          "".join(cs)
          for cs in take(
              2**width + plus_one,
              product([chr(c) for c in range(256)], repeat=length),
          )
      ]
  
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 15 for calling the LabelArrayTestCase obj's underlying member method code with example usage: obj.create_categories(width, plus_one) and returns: unknown