code: def test_reduce_error(self):
      self.assertRaises(TypeError, self.phi1.reduce, "x1")
      self.assertRaises(TypeError, self.phi1.reduce, set(["x", "y"]))
      self.assertRaises(TypeError, self.phi1.reduce, {"x": 1, "y": 1})
  
      self.assertRaises(TypeError, self.phi4.reduce, "x4")
      self.assertRaises(
          TypeError, self.phi4.reduce, set(["x1", "x2", "x3"])
      )
      self.assertRaises(
          TypeError, self.phi4.reduce, {"x1": 1, "x2": 1, "x3": 1}
      )
  
      self.assertRaises(ValueError, self.phi1.reduce, [("z", 3)])
      self.assertRaises(
          ValueError, self.phi1.reduce, [("x", 0), ("y", 1), ("z", 4)]
      )
  
      self.assertRaises(ValueError, self.phi4.reduce, [("x4", 7)])
      self.assertRaises(
          ValueError,
          self.phi4.reduce,
          [("x1", 1), ("x2", 2), ("x3", 3), ("x4", 4)],
      )
  
imports: import unittest
  import numpy
  import numpy.testing
  from scipy.special import beta
  from scipy.stats import multivariate_normal
  from pgmpy.factors.continuous import ContinuousFactor
label_desc: Use image node_id 9 for calling the TestContinuousFactorMethods obj's underlying member method code with example usage: obj.test_reduce_error() without return types