@Override
    public void refresh() {
        if (credentialsFetcher != null) {
            credentialsFetcher.refresh();
        }
    }
{@inheritDoc}

@throws AmazonClientException if {@link SDKGlobalConfiguration#isEc2MetadataDisabled()} is true
aws-java-sdk-core/src/main/java/com/amazonaws/auth/InstanceProfileCredentialsProvider.java