code: def _add_fp32_casts(block, boundary_vars):
      new_boundary_vars = []
      for var in boundary_vars:
          if var.dtype != types.fp16:
              new_boundary_vars.append(var)
          else:
              fp32_var = mb.cast(x=var, dtype="fp32", name=var.name)
              new_boundary_vars.append(fp32_var)
      return new_boundary_vars
  
imports: import argparse
  from collections import OrderedDict
  import coremltools
  from coremltools.converters.mil import Block, Program, Var
  from coremltools.converters.mil.frontend.milproto.load import load
  from coremltools.converters.mil.mil import Builder
  from coremltools.converters.mil.mil import Placeholder
  from coremltools.converters.mil.mil import types
  from coremltools.converters.mil.mil.passes.helper import block_context_manager
  from coremltools.converters.mil.mil.passes.pass_registry import PASS_REGISTRY
  from coremltools.converters.mil.testing_utils import random_gen_input_feature_type
  import gc
  import logging
  import numpy
  import os
  from python_coreml_stable_diffusion import torch2coreml
  import shutil
  import time
label_desc: Use image node_id 5 for calling a global function with example usage: _add_fp32_casts(block, boundary_vars) and returns: new_boundary_vars