text run at (0,0) width 182: "The green box should obscure"
text run at (0,20) width 198: "the red box, and move when you"
text run at (0,40) width 109: "drag the scrollbar."
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+layer at (50,50) size 202x202 clip at (51,51) size 185x200 scrollY 50.00 scrollHeight 550
RenderBlock {DIV} at (0,0) size 202x202 [border: (1px solid #000000)]
RenderBlock {DIV} at (1,51) size 185x500
layer at (51,51) size 100x100