code: def test_combine_datetime_with_float(self):
      # Test with both float-type factors and numeric values.
      for float_value in (self.f, float64(1.0), 1.0):
          for op, sym in ((add, "+"), (mul, "*")):
              with self.assertRaises(TypeError) as e:
                  op(self.f, self.d)
              message = e.exception.args[0]
              expected = (
                  "Don't know how to compute float64 {sym} datetime64[ns].\n"
                  "Arithmetic operators are only supported between Factors"
                  " of dtype 'float64'."
              ).format(sym=sym)
              self.assertEqual(message, expected)
  
              with self.assertRaises(TypeError) as e:
                  op(self.d, self.f)
              message = e.exception.args[0]
              expected = (
                  "Don't know how to compute datetime64[ns] {sym} float64.\n"
                  "Arithmetic operators are only supported between Factors"
                  " of dtype 'float64'."
              ).format(sym=sym)
              self.assertEqual(message, expected)
  
imports: from itertools import permutations
  from operator import add, ge, gt, le, lt, methodcaller, mul, ne, sub
  from string import ascii_uppercase
  from unittest import TestCase
  import numpy
  from numpy import arange, array, eye, float64, full, isnan, zeros
  from pandas import DataFrame, date_range, Int64Index
  from catalyst.pipeline import Factor, Filter
  from catalyst.pipeline.expression import NumericalExpression, NUMEXPR_MATH_FUNCS
  from catalyst.testing import check_allclose
  from catalyst.utils.numpy_utils import datetime64ns_dtype, float64_dtype
label_desc: Use image node_id 8 for calling the NumericalExpressionTestCase obj's underlying member method code with example usage: obj.test_combine_datetime_with_float() without return types