```python
parts = []
if self.package_id:
    parts.append(unicode(package_id))
if self.branch:
    parts.append(u"{prefix}{branch}".format(prefix=BRANCH_PREFIX, branch=self.branch))
if self.version_guid:
    parts.append(u"{prefix}{guid}".format(prefix=VERSION_PREFIX, guid=self.version_guid))
result = u"/".join(parts)
```