code: @Override
  	public ValueSnak getValueSnak(PropertyIdValue propertyId, Value value) {
  		return new ValueSnakImpl(propertyId, value);
  	}
docs: Creates a {@link ValueSnakImpl}. Value snaks in JSON need to know the
  datatype of their property, which is not given in the parameters of this
  method. The snak that will be returned will use a default type based on
  the kind of value that is used (usually the "simplest" type for that
  value). This may not be desired.
  
  @see DataObjectFactory#getValueSnak(PropertyIdValue, Value)