code: def default(session):
      
      # Install all test dependencies, then install local packages in-place.
      session.install('mock', 'pytest', 'pytest-cov')
      for local_dep in LOCAL_DEPS:
          session.install('-e', local_dep)
      session.install('-e', '.')
  
      # Run py.test against the unit tests.
      session.run(
          'py.test',
          '--quiet',
          '--cov=google.cloud.storage',
          '--cov=tests.unit',
          '--cov-append',
          '--cov-config=.coveragerc',
          '--cov-report=',
          '--cov-fail-under=97',
          'tests/unit',
          *session.posargs
      )
docs: Default unit test session.
  
      This is intended to be run **without** an interpreter set, so
      that the current ``python`` (on the ``PATH``) or the version of
      Python corresponding to the ``nox`` binary the ``PATH`` can
      run the tests.