@Override
  public SamzaRelConverter create(SystemStream systemStream, RelSchemaProvider schemaProvider, Config config) {
    return relConverters.computeIfAbsent(systemStream,
      ss -> new AvroRelConverter(ss, (AvroRelSchemaProvider) schemaProvider, config));
  }
Avro Schema Resolver that uses static config to return a schema for a SystemStream.
Schemas are configured using the config of format {systemName}.{streamName}.schema.
samza-sql/src/main/java/org/apache/samza/sql/avro/AvroRelConverterFactory.java