docstr: Test running with no benchmark provided.
  
  We should have no benchmark sid and have a returns series of all zeros.
docstr_tok: ["Test","running","with","no","benchmark","provided",".","We","should","have","no","benchmark","sid","and","have","a","returns","series","of","all","zeros","."]
code: def test_no_benchmark(self):
      """Test running with no benchmark provided.
  
      We should have no benchmark sid and have a returns series of all zeros.
      """
      spec = BenchmarkSpec.from_cli_params(
          no_benchmark=False,
          benchmark_sid=None,
          benchmark_symbol=None,
          benchmark_file=None,
      )
  
      sid, returns = self.resolve_spec(spec)
  
      self.assertIs(sid, None)
      self.assertIs(returns, None)
  
      warnings = self.logs_at_level(logbook.WARNING)
      expected = [
          "No benchmark configured. Assuming algorithm calls set_benchmark.",
          "Pass --benchmark-sid, --benchmark-symbol, or --benchmark-file to set a source of benchmark returns.",  # noqa
          "Pass --no-benchmark to use a dummy benchmark of zero returns.",
      ]
      assert_equal(warnings, expected)
  
imports: import logbook
  import numpy
  import pandas
  from pandas.util.testing import assert_series_equal
  from zipline.data.data_portal import DataPortal
  from zipline.errors import BenchmarkAssetNotAvailableTooEarly, BenchmarkAssetNotAvailableTooLate, InvalidBenchmarkAsset
  from zipline.sources.benchmark_source import BenchmarkSource
  from zipline.utils.run_algo import BenchmarkSpec
  from zipline.testing import MockDailyBarReader, create_minute_bar_data, parameter_space, tmp_bcolz_equity_minute_bar_reader
  from zipline.testing.predicates import assert_equal
  from zipline.testing.fixtures import WithAssetFinder, WithDataPortal, WithSimParams, WithTmpDir, WithTradingCalendars, ZiplineTestCase
  from zipline.testing.core import make_test_handler
label_desc: Use image node_id 6 for calling the BenchmarkSpecTestCase obj's underlying member method code with example usage: obj.test_no_benchmark() without return types