public void scrollViewportUp() {
		VtLine temp = lines.remove(scrollEnd - 1);
		temp.reset(cols);
		lines.add(scrollStart, temp);
	}
Scroll the viewport up a line

<p>
The lines are shifted downward. The line at the bottom of the viewport is removed, and a
blank line is inserted at the top of the viewport.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/terminal/vt/VtBuffer.java