class_docstr: Tests for verifying that SimplePipelineEngine calls hooks as expected.
      
class_docstr_tok: ["Tests","for","verifying","that","SimplePipelineEngine","calls","hooks","as","expected","."]
code: def init_instance_fixtures(self):
      super(HooksTestCase, self).init_instance_fixtures()
      # Clear out the global testing hook after each test run.
      self.add_instance_callback(self.global_testing_hook.clear)
  
imports: import itertools
  from operator import attrgetter
  import numpy
  import pandas
  import toolz
  from zipline.pipeline import Pipeline
  from zipline.pipeline.classifiers import Everything
  from zipline.pipeline.domain import US_EQUITIES
  from zipline.pipeline.factors import CustomFactor
  from zipline.pipeline.data import Column, DataSet
  from zipline.pipeline.data.testing import TestingDataSet
  from zipline.pipeline.hooks.testing import TestingHooks
  from zipline.pipeline.hooks.progress import ProgressHooks, repr_htmlsafe, TestingProgressPublisher
  from zipline.pipeline.term import AssetExists, ComputableTerm, LoadableTerm
  from zipline.testing import parameter_space
  from zipline.testing.fixtures import ZiplineTestCase, WithSeededRandomPipelineEngine
  from zipline.testing.predicates import assert_almost_equal, instance_of
label_desc: Use image node_id 2 for calling the HooksTestCase obj's underlying member method code with example usage: obj.init_instance_fixtures() without return types