wallet-core/node_modules/node-fetch/lib/fetch-error.js

/**
 * fetch-error.js
 *
 * FetchError interface for operational errors
 */

module.exports = FetchError;

/**
 * Create FetchError instance
 *
 * @param   String      message      Error message for human
 * @param   String      type         Error type for machine
 * @param   String      systemError  For Node.js system error
 * @return  FetchError
 */
function FetchError(message, type, systemError) {

	this.name = this.constructor.name;
	this.message = message;
	this.type = type;

	// when err.type is `system`, err.code contains system error code
	if (systemError) {
		this.code = this.errno = systemError.code;
	}

	// hide custom error implementation details from end-users
	Error.captureStackTrace(this, this.constructor);
}

require('util').inherits(FetchError, Error);