@Override
  public Collection<UdfMetadata> getUdfs() {
    return udfs;
  }
An UDF resolver implementation that uses reflection to discover the subtypes
of the {@link SamzaSqlUdf} from the classpath. Performs the validation to
ensure that all subtypes of {@link SamzaSqlUdf} extend and implement the
method annotated with {@link SamzaSqlUdfMethod}.
samza-sql/src/main/java/org/apache/samza/sql/udf/ReflectionBasedUdfResolver.java