code: package edu.jhu.thrax.hadoop.extraction;
  
  import org.apache.hadoop.io.LongWritable;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.mapreduce.Mapper;
  
  import edu.jhu.thrax.hadoop.datatypes.AlignedRuleWritable;
  import edu.jhu.thrax.hadoop.datatypes.Annotation;
  
  public class RuleWritableExtractorFactory {
    public static RuleWritableExtractor create(
        Mapper<LongWritable, Text, AlignedRuleWritable, Annotation>.Context context) {
      return new HierarchicalRuleWritableExtractor(context);
    }
  }
  