public int getVirtualMinY() {
		return Math.min(getVirtualStartY(), getVirtualEndY());
	}
Returns a top y position assuming rows are one million pixels apart for comparison purposes. 
It takes into account the assigned offsets of the attached rows. This method depends on
row offsets having already been assigned.
@return a virtual top y position only useful for comparison purposes.
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/graph/layout/flowchart/ColumnSegment.java