public void col(V vertex, int col) {
		GridPoint gridPoint = vertexPoints.get(vertex);
		gridPoint.col = col;
		gridBounds.update(gridPoint);
	}
Returns the column of the initial vertex in this grid.
@return the column of the initial vertex in this grid
Ghidra/Framework/Graph/src/main/java/ghidra/graph/viewer/layout/GridLocationMap.java