# changesSince abstract method

PropertyValues changesSince(

1. PropertyValues old

)

Computes the set of properties that differ compared to another `old` PropertyValues.

This method is useful for detecting changes between two property sets, such as during configuration updates or hot reload.

`old`: The previous property values to compare against Returns a new PropertyValues containing only the changed properties

Example:

    final old = MutablePropertyValues()
      ..addPropertyValueByName('host', '127.0.0.1');
    final current = MutablePropertyValues()
      ..addPropertyValueByName('host', 'localhost');

    final diff = current.changesSince(old);
    print(diff.getPropertyValue('host')?.value); // 'localhost'

## Implementation

    PropertyValues changesSince(PropertyValues old);