public BasicSessionCredentials(string accessKeyId, string accessKeySecret,string sessionToken, long roleSessionDurationSeconds = 0){if (accessKeyId == null){throw new ArgumentOutOfRangeException("Access key ID cannot be null.");}if (accessKeySecret == null){throw new ArgumentOutOfRangeException("Access key secret cannot be null.");}this.accessKeyId = accessKeyId;this.accessKeySecret = accessKeySecret;this.sessionToken = sessionToken;this.roleSessionDurationSeconds = roleSessionDurationSeconds;sessionStartedTimeInMilliSeconds = DateTime.UtcNow.currentTimeMillis();}