code: def test_time_series_slope_against_simple_cases(slope):
      """Test time series slope against simple cases."""
      x = np.arange(1, 10)
      y = x * slope
      np.testing.assert_almost_equal(_slope(y), slope, decimal=10)
  
imports: import numpy
  import pytest
  from scipy.stats import linregress
  from sktime.utils._testing.forecasting import _generate_polynomial_series
  from sktime.utils.slope_and_trend import _fit_trend, _slope
label_desc: Use image node_id 2 for calling a global function with example usage: test_time_series_slope_against_simple_cases(slope) without return types