class HiddenSubsetStrategy implements Strategy {

	static getTests() {
		[
			new Test(
				'.6.39.1....315..9.19.4263..83.57941.9...61....51.43..9419635827.2.9845.1.8.71294.',
				{
					def cell
					for (c in 8..9) {
						cell = it.getCell(5, c)
						for (n in [1,2,4,6,7,8,9]) {
							if (cell.hasMark(n)) {
								return false
							}
						}
					}
					true
				}
			)
		]
	}

	boolean play(Board board) {
		// we don't actually need to do anything here because
		// HiddenSubset and NakedSubset are "inverses" of each
		// other across a house.  So NakedSubset will find all
		// HiddenSubsets as well.
		false
	}

}