@Override
    public void refresh() {
       provider.refresh();
    }
<p>
{@link AWSCredentialsProvider} that loads credentials from an Amazon Container (e.g. EC2)

Credentials are solved in the following order:
<ol>
    <li>
        If environment variable "AWS_CONTAINER_CREDENTIALS_RELATIVE_URI" is
        set (typically on EC2) it is used to hit the metadata service at the following endpoint: http://169.254.170.2
         (ECS). See {@link ContainerCredentialsProvider} for more
          information.
    </li>
    <li>
        If environment variable "AWS_CONTAINER_CREDENTIALS_FULL_URI" is
        set it is used to hit a metadata service at that URI. See {@link ContainerCredentialsProvider} for more
        information.
    </li>
    <li>
        If neither of the above environment variables are specified credentials are attempted to be loaded from Amazon EC2
        Instance Metadata Service using the {@link InstanceProfileCredentialsProvider}.
    </li>
</ol>
aws-java-sdk-core/src/main/java/com/amazonaws/auth/EC2ContainerCredentialsProviderWrapper.java