def filter_file_list(self, file_prefix):
        """
        Filter a list of filenames based on a given file prefix.

        Args:
            file_prefix(str): A string representing the prefix of the filenames to filter.

        Returns:
            list: A list of filenames that are created before 15 minutes ago.
        """
        __method_name = inspect.currentframe().f_code.co_name
        try:
            parent_file = ShareDirectoryClient.from_connection_string(
                conn_str=consts.CONN_STRING,
                share_name=consts.FILE_SHARE_NAME_DATA,
                directory_path="",
            )

            filenames = self.list_file_names_in_file_share(parent_file, file_prefix)
            if filenames is None:
                applogger.info(
                    self.log_format.format(
                        consts.LOGS_STARTS_WITH,
                        __method_name,
                        self.azure_function_name,
                        "No files found",
                    )
                )
                return []
            applogger.info(
                self.log_format.format(
                    consts.LOGS_STARTS_WITH,
                    __method_name,
                    self.azure_function_name,
                    "Sort Files by current timestamp",
                )
            )
            sorted_filenames = sorted(filenames, key=self.get_timestamp)

            applogger.info(
                self.log_format.format(
                    consts.LOGS_STARTS_WITH,
                    __method_name,
                    self.azure_function_name,
                    "Filter files created before 15 mins.",
                )
            )
            current_time = int(time.time())

            filtered_filenames = [
                filename
                for filename in sorted_filenames
                if ((current_time - self.get_timestamp(filename)) > consts.MAX_FILE_AGE_FOR_INDICATORS)
            ]
            applogger.info(
                self.log_format.format(
                    consts.LOGS_STARTS_WITH,
                    __method_name,
                    self.azure_function_name,
                    "Filtered File count = {}".format(len(filtered_filenames)),
                )
            )
            return filtered_filenames
        except InfobloxException:
            raise InfobloxException()
        except Exception as error:
            applogger.error(
                self.log_format.format(
                    consts.LOGS_STARTS_WITH,
                    __method_name,
                    self.azure_function_name,
                    consts.UNEXPECTED_ERROR_MSG.format(error),
                )
            )
            raise InfobloxException()

        Filter a list of filenames based on a given file prefix.

        Args:
            file_prefix(str): A string representing the prefix of the filenames to filter.

        Returns:
            list: A list of filenames that are created before 15 minutes ago.
        
Solutions/Infoblox/Data Connectors/InfobloxCloudDataConnector/SharedCode/utils.py