This class provides methods to implement fetch with retries.\nThe retries use exponential backoff strategy\nwith defaults set to max of 3 retries and initial Delay as 100ms
\nThis provides a wrapper for fetch that facilitates proxy auth authorization.
\nfunctionReturn the appropriate Fetch function depending on proxy settings.
\nnumberParse the Retry-After header\nSpec: https://tools.ietf.org/html/rfc7231#section-7.1.3
\nobjectFetch Retry Options
\nobjectProxy Auth Options
\nPromise.<Response>\n\n\n\n### new HttpExponentialBackoff([options])\nCreates an instance of HttpExponentialBackoff\n\n\n| Param | Type | Description |\n| --- | --- | --- |\n| [options] | object | configuration options |\n| [options.logLevel] | string | the log level to use (default: process.env.LOG_LEVEL or 'info') |\n| [options.logRetryAfterSeconds] | number | the number of seconds after which to log a warning if the Retry-After header is greater than the number of seconds. Set to 0 to disable. |\n\n\n\n### httpExponentialBackoff.exponentialBackoff(url, requestOptions, [retryOptions], [retryOn], [retryDelay]) ⇒ Promise.<Response>\nThis function will retry connecting to a url end-point, with\nexponential backoff. Returns a Promise.\n\n**Kind**: instance method of [HttpExponentialBackoff](#HttpExponentialBackoff) \n**Returns**: Promise.<Response> - Promise object representing the http response \n\n| Param | Type | Description |\n| --- | --- | --- |\n| url | string | endpoint url |\n| requestOptions | object \\| Request | request options |\n| [retryOptions] | [RetryOptions](#RetryOptions) | (optional) retry options |\n| [retryOn] | function \\| Array | (optional) Function or Array. If provided, will be used instead of the default |\n| [retryDelay] | function \\| number | (optional) Function or number. If provided, will be used instead of the default |\n\n\n\n## ProxyFetch\nThis provides a wrapper for fetch that facilitates proxy auth authorization.\n\n**Kind**: global class \n\n* [ProxyFetch](#ProxyFetch)\n * [new ProxyFetch(proxyOptions)](#new_ProxyFetch_new)\n * [.fetch(resource, options)](#ProxyFetch+fetch) ⇒ Promise.<Response>\n\n\n\n### new ProxyFetch(proxyOptions)\nInitialize this class with Proxy auth options\n\n\n| Param | Type | Description |\n| --- | --- | --- |\n| proxyOptions | [ProxyOptions](#ProxyOptions) | the auth options to connect with |\n\n\n\n### proxyFetch.fetch(resource, options) ⇒ Promise.<Response>\nFetch function, using the configured fetch options, and proxy options (set in the constructor).\n\n**Kind**: instance method of [ProxyFetch](#ProxyFetch) \n**Returns**: Promise.<Response> - Promise object representing the http response \n\n| Param | Type | Description |\n| --- | --- | --- |\n| resource | string \\| Request | the url or Request object to fetch from |\n| options | object | the fetch options |\n\n\n\n## createFetch([proxyOptions]) ⇒ function\nReturn the appropriate Fetch function depending on proxy settings.\n\n**Kind**: global function \n**Returns**: function - the Fetch API function \n\n| Param | Type | Description |\n| --- | --- | --- |\n| [proxyOptions] | [ProxyOptions](#ProxyOptions) | the proxy options |\n\n\n\n## parseRetryAfterHeader(header) ⇒ number\nParse the Retry-After header\nSpec: [https://tools.ietf.org/html/rfc7231#section-7.1.3](https://tools.ietf.org/html/rfc7231#section-7.1.3)\n\n**Kind**: global function \n**Returns**: number - Number of milliseconds to sleep until the next call to getEventsFromJournal \n\n| Param | Type | Description |\n| --- | --- | --- |\n| header | string | Retry-After header value |\n\n\n\n## RetryOptions : object\nFetch Retry Options\n\n**Kind**: global typedef \n**Properties**\n\n| Name | Type | Description |\n| --- | --- | --- |\n| maxRetries | number | the maximum number of retries to try (default:3) |\n| initialDelayInMillis | number | the initial delay in milliseconds (default:100ms) |\n| proxy | [ProxyOptions](#ProxyOptions) | the (optional) proxy auth options |\n\n\n\n## ProxyOptions : object\nProxy Auth Options\n\n**Kind**: global typedef \n**Properties**\n\n| Name | Type | Description |\n| --- | --- | --- |\n| proxyUrl | string | the proxy's url |\n| [username] | string | the username for basic auth |\n| [password] | string | the password for basic auth |\n| rejectUnauthorized | boolean | set to false to not reject unauthorized server certs |\n| [logLevel] | string | the log level to use (default: process.env.LOG_LEVEL or 'info') |\n\n### Debug Logs\n\n```bash\nLOG_LEVEL=debug