code: def generateSPV(self, output_dir: str) -> Dict[str, str]:
      output_file_map = {}
      for shader_name in self.output_shader_map:
          source_glsl = self.output_shader_map[shader_name][0]
          shader_params = self.output_shader_map[shader_name][1]
  
          with codecs.open(
              source_glsl, "r", encoding="utf-8"
          ) as input_file:
              input_text = input_file.read()
              output_text = preprocess(input_text, shader_params)
  
          glsl_out_path = os.path.join(
              output_dir, f"{shader_name}.glsl"
          )
          with codecs.open(
              glsl_out_path, "w", encoding="utf-8"
          ) as output_file:
              output_file.write(output_text)
  
          # If no GLSL compiler is specified, then only write out the generated GLSL shaders.
          # This is mainly for testing purposes.
          if self.glslc_path is not None:
              spv_out_path = os.path.join(
                  output_dir, f"{shader_name}.spv"
              )
  
              cmd = [
                  self.glslc_path,
                  "-fshader-stage=compute",
                  glsl_out_path,
                  "-o",
                  spv_out_path,
                  "--target-env=vulkan1.0",
                  "-Werror",
              ] + [
                  arg
                  for src_dir_path in self.src_dir_paths
                  for arg in ["-I", src_dir_path]
              ]
  
              print("glslc cmd:", cmd)
              subprocess.check_call(cmd)
  
              output_file_map[spv_out_path] = glsl_out_path
  
      return output_file_map
  
imports: import argparse
  import array
  import codecs
  import copy
  import glob
  import io
  import os
  import re
  import sys
  from itertools import product
  import subprocess
  import textwrap
  from dataclasses import dataclass
  from typing import Any, Dict, List, Optional, Set, Tuple, Union
  import yaml
  from yaml.constructor import ConstructorError
  from yaml.nodes import MappingNode
label_desc: Use image node_id 7 for calling the SPVGenerator obj's underlying member method code with example usage: obj.generateSPV(output_dir) and returns: output_file_map