docstr: Discretiser should accept lower boundary down to zero
code: def test_outlier_percentile_lower_boundary(self):
      """Discretiser should accept lower boundary down to zero"""
  
      Discretiser(method="outlier", outlier_percentile=0.0)
      Discretiser(method="outlier", outlier_percentile=-0.0)
      with pytest.raises(ValueError):
          Discretiser(method="outlier", outlier_percentile=-0.1)
  
imports: import math
  import numpy
  import pytest
  from causalnex.discretiser import Discretiser
label_desc: Use image node_id 1 for calling the TestOutlier obj's underlying member method code with example usage: obj.test_outlier_percentile_lower_boundary() without return types