private void lighten(FGEdge e) {

		if (!getLayoutOptions().useDimmedReturnEdges()) {
			return;
		}

		// assumption: edges that move to the left in this layout are return flows that happen
		//             after the code block has been executed.  We dim those a bit so that they
		//             produce less clutter.
		e.setDefaultAlpha(.25);
	}
An amount by which edges entering a vertex from the left are offset to avoid overlapping
Ghidra/Features/FunctionGraphDecompilerExtension/src/main/java/ghidra/app/plugin/core/functiongraph/graph/layout/DecompilerNestedLayout.java