liquibase-core/src/main/java/liquibase/change/ChangeMetaData.java
public Map<String, ChangeParameterMetaData> getSetParameters(Change change) {
        Map<String, ChangeParameterMetaData> returnMap = new HashMap<>();
        for (Map.Entry<String, ChangeParameterMetaData> entry : getParameters().entrySet()) {
            if (entry.getValue().getCurrentValue(change) != null) {
                returnMap.put(entry.getKey(), entry.getValue());
            }
        }
        return Collections.unmodifiableMap(returnMap);
    }
public Map<String, ChangeParameterMetaData> getSetParameters(Change change) {
        Map<String, ChangeParameterMetaData> returnMap = new HashMap<>();
        for (Map.Entry<String, ChangeParameterMetaData> entry : getParameters().entrySet()) {
            if (entry.getValue().getCurrentValue(change) != null) {
                returnMap.put(entry.getKey(), entry.getValue());
            }
        }
        return Collections.unmodifiableMap(returnMap);
    }
Return the parameters of the given change that are set to a non-null value. Will never return a null map, only an empty or populated map.