class_docstr: Holds shared variables needed for transcription.
class_docstr_tok: ["Holds","shared","variables","needed","for","transcription","."]
code: def __init__(self, weights_dir=""):
      self.name_to_var = {}  # mapping from name -> var object
      self.blob_reader_from_filename = (
          {}
      )  # mapping from filename -> BlobReader object
      self.weights_dir = weights_dir
  
imports: import os
  import numpy
  from coremltools import _logger
  from coremltools.converters.mil._deployment_compatibility import AvailableTarget
  from coremltools.converters.mil.backend.mil import helper
  from coremltools.converters.mil.mil import Block
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import Function, ListVar, Placeholder, Program, TupleInputType, Var, mil_list, types
  from coremltools.converters.mil.mil.block import curr_block
  from coremltools.converters.mil.mil.ops.registry import SSAOpRegistry
  from coremltools.proto import MIL_pb2
  from coremltools.proto import Model_pb2
  from .helper import proto_to_types
label_desc: Use image node_id 1 to create a new TranscriptionContext object  with example: obj = TranscriptionContext(weights_dir)