code: def _FormatPropertyName(self, property_name):
      
      # TODO: Add Unicode support.
      fix_key = re.sub(r'(.)([A-Z][a-z]+)', r'\1_\2', property_name)
      return re.sub(r'([a-z0-9])([A-Z])', r'\1_\2', fix_key).lower()
docs: Formats a camel case property name as snake case.
  
      Args:
        property_name (str): property name in camel case.
  
      Returns:
        str: property name in snake case.