@Override
  public boolean removeAll(Collection c) {
    if (c instanceof StructSet) {
      return removeAll((StructSet) c);
    } else {
      boolean modified = false;
      for (Object o : c) {
        modified |= remove(o);
      }
      return modified;
    }
  }
Remove the field values from a struct of the correct type
geode-core/src/main/java/org/apache/geode/cache/query/internal/StructSet.java