in src/main/java/com/epam/eco/commons/diff/Diff.java [35:42]
public Diff(String originalId, String revisionId, List<String> diff) {
Validate.isTrue(revisionId != null || originalId != null,
"Original id or revision id can't be null");
this.originalId = originalId;
this.revisionId = revisionId;
this.diff = diff == null ? Collections.emptyList() : Collections.unmodifiableList(new ArrayList<>(diff));
}