public static DiagramShape createArrowhead(TextGrid grid, TextGrid.Cell cell, int cellXSize, int cellYSize) {
		if(!grid.isArrowhead(cell)) return null;
		if(grid.isNorthArrowhead(cell)) return createNorthArrowhead(grid, cell, cellXSize, cellYSize);
		if(grid.isSouthArrowhead(cell)) return createSouthArrowhead(grid, cell, cellXSize, cellYSize);
		if(grid.isWestArrowhead(cell)) return createWestArrowhead(grid, cell, cellXSize, cellYSize);
		if(grid.isEastArrowhead(cell)) return createEastArrowhead(grid, cell, cellXSize, cellYSize);
		return null;
	}