class_docstr: Test environment for different dtype conversion semantics.
code: def __init__(self, promo_mode):
      self._old_promo_mode = ops.promo_mode_enum_to_string(
          ops.get_dtype_conversion_mode()
      )
      self._new_promo_mode = promo_mode
  
file_path: tensorflow-upstream/tensorflow/python/ops/weak_tensor_test_util.py
imports: import numpy
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework.weak_tensor import WeakTensor
label_desc: Use image node_id 1 to create a new DtypeConversionTestEnv object  with example: obj = DtypeConversionTestEnv(promo_mode)