code: def test_expect_dtypes_with_tuple(self):
      allowed_dtypes = (dtype("datetime64[ns]"), dtype("float"))
  
      @expect_dtypes(a=allowed_dtypes)
      def foo(a, b):
          return a, b
  
      for d in allowed_dtypes:
          good_a = arange(3).astype(d)
          good_b = object()
          ret_a, ret_b = foo(good_a, good_b)
          self.assertIs(good_a, ret_a)
          self.assertIs(good_b, ret_b)
  
      with self.assertRaises(TypeError) as e:
          foo(arange(3, dtype="uint32"), object())
  
      expected_message = (
          "{qualname}() expected a value with dtype 'datetime64[ns]' "
          "or 'float64' for argument 'a', but got 'uint32' instead."
      ).format(qualname=qualname(foo))
      self.assertEqual(e.exception.args[0], expected_message)
  
imports: from operator import attrgetter
  from types import FunctionType
  from unittest import TestCase
  from nose_parameterized import parameterized
  from numpy import arange, array, dtype
  import pytz
  from six import PY3
  from zipline.utils.preprocess import call, preprocess
  from zipline.utils.input_validation import expect_dimensions, ensure_timezone, expect_element, expect_dtypes, expect_types, optional, optionally
label_desc: Use image node_id 16 for calling the PreprocessTestCase obj's underlying member method code with example usage: obj.test_expect_dtypes_with_tuple() and returns: a,  b