docstr: Test initialization with a non-string name.
docstr_tok: ["Test","initialization","with","a","non-string","name","."]
code: def test_initialization_non_string_name(self):
      """Test initialization with a non-string name."""
      with self.assertRaisesRegex(TypeError, "'name' must be a string"):
          DTypePolicy(123)
  
imports: from keras.mixed_precision import DTypePolicy
  from keras.mixed_precision import dtype_policy
  from keras.mixed_precision import set_dtype_policy
  from keras.testing import test_case
label_desc: Use image node_id 3 for calling the DTypePolicyTest obj's underlying member method code with example usage: obj.test_initialization_non_string_name() without return types