code: def validate_files_exist(self, folder, resources):
          
          for item in resources:
              file_name = item.get('path')
              full_path = os.path.join(folder, file_name)
              if not os.path.isfile(full_path):
                  raise ValueError('%s does not exist' % full_path)
docs: ensure that one or more resource files exist in a folder
  
              Parameters
              ==========
              folder: the folder to validate
              resources: one or more resources to validate within the folder