code: package edu.jhu.thrax.hadoop.features.annotation;
  
  import java.io.IOException;
  import java.util.Set;
  
  import org.apache.hadoop.io.Writable;
  import org.apache.hadoop.mapreduce.Reducer.Context;
  
  import edu.jhu.thrax.hadoop.datatypes.Annotation;
  import edu.jhu.thrax.hadoop.datatypes.RuleWritable;
  import edu.jhu.thrax.hadoop.features.Feature;
  import edu.jhu.thrax.hadoop.jobs.ThraxJob;
  
  public interface AnnotationFeature extends Feature {
  
    @SuppressWarnings("rawtypes")
    public void init(Context context) throws IOException, InterruptedException;
  
    public Writable score(RuleWritable r, Annotation annotation);
  
    // TODO: move this into its own interface, have AF extend it.
    public Set<Class<? extends ThraxJob>> getPrerequisites();
  }
  