code: def test_color_assert_int8_user_error():
      with Color("WHITE") as c:
          with raises(TypeError):
              c._assert_int8(0.123)
          with raises(ValueError):
              c._assert_int8(-1)
          with raises(ValueError):
              c._assert_int8(0xFFFFF)
  
imports: import ctypes
  import time
  import warnings
  from pytest import mark, raises
  from wand.color import Color
  from wand.compat import xrange
  from wand.version import QUANTUM_DEPTH, MAGICK_VERSION_INFO
label_desc: Use image node_id 37 for calling a global function with example usage: test_color_assert_int8_user_error() without return types