docs: private static <T> Map<Field, TypeSerializer<?>> buildNewFieldSerializersIndex(PojoSerializer<T> newPojoSerializer) {
  		final Field[] newFields = newPojoSerializer.getFields();
  		final TypeSerializer<?>[] newFieldSerializers = newPojoSerializer.getFieldSerializers();
  
  		checkState(newFields.length == newFieldSerializers.length);
  
  		int numFields = newFields.length;
  		final Map<Field, TypeSerializer<?>> index = new HashMap<>(numFields);
  		for (int i = 0; i < numFields; i++) {
  			index.put(newFields[i], newFieldSerializers[i]);
  		}
  
  		return index;
  	}