code: def __init__(self, fd_spec):
      self._fd_spec = fd_spec
  
imports: import atexit
  import os
  import shutil
  import tempfile
  import warnings
  from copy import deepcopy
  import numpy
  import numpy
  from coremltools import ComputeUnit
  from coremltools._deps import _HAS_TF_1, _HAS_TF_2, _HAS_TORCH
  from coremltools.converters.mil.mil.program import Program
  from ..proto import FeatureTypes_pb2
  from ..proto import MIL_pb2
  from ..proto import Model_pb2
  from .utils import _MLMODEL_EXTENSION, _MLPACKAGE_AUTHOR_NAME, _MLPACKAGE_EXTENSION, _MODEL_FILE_NAME, _WEIGHTS_DIR_NAME, _create_mlpackage, _has_custom_layer, _is_macos, _macos_version
  from .utils import load_spec
  from .utils import save_spec
label_desc: Use image node_id 1 to create a new _FeatureDescription object  with example: obj = _FeatureDescription(fd_spec)