anchor.diff:  }
   
   class _CompactIterator<E> implements Iterator<E> {
  -  final _table;
  +  final _HashBase _table;
     final List _data;
     final int _len;
     int _offset;
  
positive.code:   }
  }
  
  abstract class _LinkedHashMapMixin<K, V> implements _HashVMBase {
    int _hashCode(e);
    bool _equals(e1, e2);
    int get _checkSum;
  
negative.code:   int get _checkSum => _usedData + _deletedKeys;
    bool _isModifiedSince(List oldData, int oldCheckSum) =>
        !identical(_data, oldData) || (_checkSum != oldCheckSum);
  
    int get length;
  }
  
  class _OperatorEqualsAndHashCode {
  