code: def plugin_list(plugin_dir):
      if plugin_dir is not None and os.path.isdir(plugin_dir):
          file_list = glob.glob(os.path.join(plugin_dir, "[!_]*.py"))
          return [os.path.basename(f)[:-3] for f in file_list]
      return []
  
imports: import glob
  import importlib
  import importlib.util
  import inspect
  import logging
  import os
  import re
  import sys
  import traceback
  from cellprofiler_core.constants.modules import all_modules
  from cellprofiler_core.constants.modules import pymodules
  from cellprofiler_core.constants.reader import ALL_READERS, BAD_READERS, AVAILABLE_READERS
  from cellprofiler_core.preferences import get_plugin_directory, config_read_typed
  from cellprofiler_core.module import Module
  from cellprofiler_core.reader import Reader
label_desc: Use image node_id 1 for calling a global function with example usage: plugin_list(plugin_dir) and returns: list, unknown