code: def get_filename_by_class(self, current_class):
          
          for digest, dx in self.analyzed_vms.items():
              if dx.is_class_present(current_class.get_name()):
                  return self.analyzed_digest[digest]
          return None
docs: Returns the filename of the DEX file where the class is in.
  
          Returns the first filename this class was present.
          For example, if you analyzed an APK, this should return the filename of
          the APK and not of the DEX file.
  
          :param current_class: ClassDefItem
          :returns: None if class was not found or the filename