anchor.diff:  
       test('remove data. (T07)', () {
         // given
  -      Future toRemove = ready.then((_) => months.add(new Map.from(january), 'John Doe'))
  +      Future toRemove = ready.then((_) => months.add(clone(january), 'John Doe'))
   
         // when
           .then((_) => months.remove('january', 'Michael Smith'));
  
positive.code:     test('deprecatedChange data. (T10)', () {
        // given
        Map january2 = {'name': 'January2', 'number': 4, '_id': 'january'};
        return ready.then((_) => months.add(new Map.from(january), 'John Doe'))
  
        // when
          .then((_) => months.deprecatedChange('january', new Map.from(january2), 'Michael Smith'))
          .then((_) => months.data())
          .then((data){
  
  
negative.code:       Future multipleAccess =
            ready.then((_) => months.data()).then((data) => dataStart = data['data'] )
  
         .then((_) => months.addAll(clone([january, february, march, april]), 'John Doe'))
         .then((_) => months.change('january', january2, 'John Doe'))
         .then((_) => months.remove('february', 'John'))
         .then((_) => months.add(clone(february), 'John Doe'))
         .then((_) => months.remove('april', 'John'))
         .then((_) => months.add(clone(may), 'John Doe'))
         .then((_) => months.change('march', march2, 'John Doe'))
         .then((_) => months.change('january', january, 'John Doe'))
         .then((_) => months.data()).then((data) => dataEnd = data['data'] );
  