code: def test_algorithm_beta(self):
      # Beta is calculated by a empyrical function so testing
      # of period beta will be limited to determine if the value is
      # numerical. This tests for its existence and format.
      for period in PERIODS:
          self.assertTrue(
              all(
                  isinstance(x["beta"], float) or x["beta"] is None
                  for x in self.metrics[period]
              )
          )
  
imports: import datetime
  import pandas
  import numpy
  from zipline.utils import factory
  from zipline.finance.trading import SimulationParameters
  import zipline.testing.fixtures
  from zipline.finance.metrics import _ClassicRiskMetrics
label_desc: Use image node_id 11 for calling the TestRisk obj's underlying member method code with example usage: obj.test_algorithm_beta() without return types