@Override
  public AWSCredentials getCredentials() {
    return creds;
  }
AWSCredentialsProvider implementation that takes in accessKey and secretKey directly. Requires both accessKey and
secretKey to be non-null for it to create a BasicAWSCredentials instance. Otherwise, it creates an AWSCredentials
instance with null keys.
samza-aws/src/main/java/org/apache/samza/system/kinesis/KinesisAWSCredentialsProvider.java