I guess the ``workspaceExists()`` call is not needed when we use ``$this->workspaceName``, so we could do:
```
        if (null !== $srcWorkspace && !$this->workspaceExists($srcWorkspace)) {
            throw new NoSuchWorkspaceException("Source workspace '$srcWorkspace' does not exist.");
        }
        $srcWorkspace = srcWorkspace ?: $this->workspaceName;
```