def validate_literal_block()

in activities.py [0:0]


    def validate_literal_block(self, data: CommentedMap, key: str, field: str):
        value = data.get(key, {}).get(field)
        if value is not None:
            if not isinstance(value, LiteralScalarString):
                if self.fix:
                    data[key][field] = LiteralScalarString(value)
                else:
                    self.log_error(f"'{field}' must use literal block syntax (|).", key)
            elif not value.endswith('\n'):
                if self.fix:
                    data[key][field] = LiteralScalarString(f"{value}\n")
                else:
                    self.log_error(f"'{field}' must end with a newline to use '|' syntax.", key)