class_docstr: Holds shared variables needed for transcription.
class_docstr_tok: ["Holds","shared","variables","needed","for","transcription","."]
code: def get_var_from_name(self, name):
      if name not in self.name_to_var:
          raise KeyError("Var {} not found".format(name))
      return self.name_to_var[name]
  
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 3 for calling the TranscriptionContext obj's underlying member method code with example usage: obj.get_var_from_name(name) and returns: self