code: private AWSCredentials retrieveAwsCredentials() {
  		if (this.awsCredentialProvider == null) {
  			if (this.username != null && this.password != null) {
  				this.logger.debug("Creating a static AWSCredentialsProvider");
  				this.awsCredentialProvider = new AWSStaticCredentialsProvider(
  						new BasicAWSCredentials(this.username, this.password));
  			}
  			else {
  				this.logger.debug("Creating a default AWSCredentialsProvider");
  				this.awsCredentialProvider = new DefaultAWSCredentialsProviderChain();
  			}
  		}
  		return this.awsCredentialProvider.getCredentials();
  	}
docs: Get the AWSCredentials. If an AWSCredentialProvider was specified, use that,
  otherwise, create a new AWSCredentialsProvider. If the username and password are
  provided, then use those directly as AWSCredentials. Otherwise us the
  {@link DefaultAWSCredentialsProviderChain} as is standard with AWS applications.
  @return the AWS credentials.