docstr: a value error should be raised if numeric split points are not monotonically increasing
code: def test_fixed_split_points_monotonic(self):
      """a value error should be raised if numeric split points are not monotonically increasing"""
  
      Discretiser(method="fixed", numeric_split_points=[-1, -0, 0, 1])
      with pytest.raises(
          ValueError,
          match="numeric_split_points must be monotonically increasing",
      ):
          Discretiser(method="fixed", numeric_split_points=[1, -1])
  
imports: import math
  import numpy
  import pytest
  from causalnex.discretiser import Discretiser
label_desc: Use image node_id 8 for calling the TestErrorHandling obj's underlying member method code with example usage: obj.test_fixed_split_points_monotonic() without return types