Place seven copies of the hexomino below in a 7x7 square such there are no sub-rectangles larger than 2x4 which contain only whole hexominos and empty squares.
(Every sub-rectangle larger than 2x4 will cut though at least one hexomino.)

+--+--+--+--+
|  |  |  |  |
+--+--+--+--+
|  |  |
+--+--+

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