public void setColumnExclusionFunction(Function<E, GridRange> excludedColumnsFunction) {
		this.excludedColumnsFunction = excludedColumnsFunction;
	}
Sets a function that can be used to prevent edges from being routed in  a range of columns.
One use of this is to prevent back edges from intersecting any child trees in its ancestor
hierarchy between the start vertex and the end vertex.  
@param excludedColumnsFunction the function to call to compute a range of columns to 
prevent routing edges.
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/graph/layout/flowchart/OrthogonalEdgeRouter.java