public static void toArray(RecordIdentifier ri, Object[] struct) {
      assert struct != null && struct.length == Field.values().length;
      if(ri == null) {
        Arrays.fill(struct, null);
        return;
      }
      struct[Field.writeId.ordinal()] = ri.getWriteId();
      struct[Field.bucketId.ordinal()] = ri.getBucketProperty();
      struct[Field.rowId.ordinal()] = ri.getRowId();
    }
Copies relevant fields from {@code ri} to {@code struct}
@param ri
@param struct must be of size Field.values().size()
ql/src/java/org/apache/hadoop/hive/ql/io/RecordIdentifier.java