Loading a graph from a file does not replace current graph

[Jackymancs4]

Describe the bug
Loading a graph from a file does not replace current graph.
It's not really a problem but the tooltip says it does.

To Reproduce
Steps to reproduce the behavior:

1. Add a node
2. Save the graph
3. Click the "Load a graph from file"
4. See that it straight up add the graph to what is already present.

Expected behavior
It should clear the current graph.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Windows
• Version master

Additional context
The behavior is ok with me. In case the following line should be amended:

Donatello/src/main/java/com/marginallyclever/donatello/actions/undoable/GraphLoadAction.java

Line 62 in 0795f09

putValue(SHORT_DESCRIPTION,"Load a graph from a file. Completely replaces the current graph.");

[i-make-robots]

Correct. It imports the graph into the existing graph so that you can combine things. If you want a new work space, use the new button first.