code: @Override
    public Converter<Schema, Schema, GenericRecord, GenericRecord> init(WorkUnitState workUnit) {
      Preconditions.checkArgument(workUnit.contains(ConfigurationKeys.CONVERTER_FILTER_FIELD_NAME),
          "Missing required property converter.filter.field for the AvroFilterConverter class.");
      Preconditions.checkArgument(workUnit.contains(ConfigurationKeys.CONVERTER_FILTER_FIELD_VALUE),
          "Missing required property converter.filter.value for the AvroFilterConverter class.");
  
      this.fieldName = workUnit.getProp(ConfigurationKeys.CONVERTER_FILTER_FIELD_NAME);
      this.fieldValue = workUnit.getProp(ConfigurationKeys.CONVERTER_FILTER_FIELD_VALUE);
      return super.init(workUnit);
    }
docs: The config must specify {@link ConfigurationKeys#CONVERTER_FILTER_FIELD_NAME} to indicate which field to retrieve
  from the Avro record and {@link ConfigurationKeys#CONVERTER_FILTER_FIELD_VALUE} to indicate the expected value of
  the field.
  {@inheritDoc}
  @see org.apache.gobblin.converter.Converter#init(org.apache.gobblin.configuration.WorkUnitState)