cdm/src/main/java/ucar/nc2/ft/point/standard/NestedTable.java
void addParentJoin(Cursor cursor) throws IOException {
    int level = cursor.currentIndex;
    Table t = getTable(level);
    if (t.extraJoins != null) {
      List<StructureData> sdata = new ArrayList<>(3);
      sdata.add(cursor.tableData[level]);
      for (Join j : t.extraJoins) {
        sdata.add(j.getJoinData(cursor));
      }
      cursor.tableData[level] = StructureDataFactory.make(sdata.toArray(new StructureData[sdata.size()]));  // LOOK should try to consolidate
    }
  }
void addParentJoin(Cursor cursor) throws IOException {
    int level = cursor.currentIndex;
    Table t = getTable(level);
    if (t.extraJoins != null) {
      List<StructureData> sdata = new ArrayList<>(3);
      sdata.add(cursor.tableData[level]);
      for (Join j : t.extraJoins) {
        sdata.add(j.getJoinData(cursor));
      }
      cursor.tableData[level] = StructureDataFactory.make(sdata.toArray(new StructureData[sdata.size()]));  // LOOK should try to consolidate
    }
  }
add table join to this cursor level