xrandr --newmode "1600x900_60.00"  118.25  1600 1696 1856 2112  900 903 908 934 -hsync +vsync
xrandr --addmode DP2 1600x900_60.00
xrandr --output DP2 --mode 1600x900_60.00

xrandr: Output DP1 is not disconnected but has no modes
xrandr: Output HDMI1 is not disconnected but has no modes
xrandr: Output HDMI2 is not disconnected but has no modes
xrandr: Output HDMI3 is not disconnected but has no modes
xrandr: Output DP1 is not disconnected but has no modes
xrandr: Output HDMI1 is not disconnected but has no modes
xrandr: Output HDMI2 is not disconnected but has no modes
xrandr: Output HDMI3 is not disconnected but has no modes
xrandr: Output DP1 is not disconnected but has no modes
xrandr: Output HDMI1 is not disconnected but has no modes
xrandr: Output HDMI2 is not disconnected but has no modes
xrandr: Output HDMI3 is not disconnected but has no modes

xrandr --output HDMI1 --off --output HDMI2 --off --output HDMI3 --off --output DP1 --off

eDP1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.00*+
   800x600       60.32    56.25
   640x480       59.94
   512x384       60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.00*
   800x600       60.32    56.25
   848x480       60.00
   640x480       59.94
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)