add the @Requires for this walker

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@762 348d0f76-0448-11de-a6fe-93d51630548a

java/src/org/broadinstitute/sting/gatk/walkers/LocusWindowWalker.java

@@ -12,6 +12,7 @@ import net.sf.samtools.SAMRecord;
  * Time: 2:52:28 PM
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+@Requires({DataSource.READS,DataSource.REFERENCE})
 public abstract class LocusWindowWalker<MapType, ReduceType> extends Walker<MapType, ReduceType> {
     // Do we actually want to operate on the context?
     public boolean filter(RefMetaDataTracker tracker, String ref, LocusContext context) {