docstr: a value error should be raised if outlier is not < 0.5
code: def test_outlier_lt_half(self):
      """a value error should be raised if outlier is not < 0.5"""
  
      Discretiser(method="outlier", outlier_percentile=0.49)
      with pytest.raises(
          ValueError,
          match="outlier_percentile must be between 0 and 0.5",
      ):
          Discretiser(method="outlier", outlier_percentile=0.5)
  
imports: import math
  import numpy
  import pytest
  from causalnex.discretiser import Discretiser
label_desc: Use image node_id 6 for calling the TestErrorHandling obj's underlying member method code with example usage: obj.test_outlier_lt_half() without return types