code: def list_primitive_files(directory):
      """returns list of files in directory that might contain primitives"""
      files = os.listdir(directory)
      keep = []
      for path in files:
          if not check_valid_primitive_path(path):
              continue
          keep.append(os.path.join(directory, path))
      return keep
  
imports: import importlib.util
  import os
  from inspect import getfullargspec, getsource, isclass
  from typing import Dict, List
  import pandas
  from woodwork import list_logical_types, list_semantic_tags, type_system
  from woodwork.column_schema import ColumnSchema
  from woodwork.logical_types import NaturalLanguage
  import featuretools
  from featuretools.primitives import NumberOfCommonWords
  from featuretools.primitives.base import AggregationPrimitive, PrimitiveBase, TransformPrimitive
  from featuretools.utils.gen_utils import Library, find_descendents
label_desc: Use image node_id 15 for calling a global function with example usage: list_primitive_files(directory) and returns: keep