setCell method
Implementation
void setCell(int index, int char, int witdh, CursorStyle style) {
final offset = index * _cellSize;
_data[offset + _cellForeground] = style.foreground;
_data[offset + _cellBackground] = style.background;
_data[offset + _cellAttributes] = style.attrs;
_data[offset + _cellContent] = char | (witdh << CellContent.widthShift);
}