liquibase-core/src/main/java/liquibase/change/ChangeFactory.java
public SortedSet<String> getDefinedChanges() {
        SortedSet<String> names = new TreeSet<>();
        for (Change change : findAllInstances()) {
            names.add(getChangeMetaData(change).getName());
        }
        return Collections.unmodifiableSortedSet(names);
    }
public SortedSet<String> getDefinedChanges() {
        SortedSet<String> names = new TreeSet<>();
        for (Change change : findAllInstances()) {
            names.add(getChangeMetaData(change).getName());
        }
        return Collections.unmodifiableSortedSet(names);
    }
Returns all defined changes in the registry. Returned set is not modifiable.