public boolean estEntoureDeMurs() {
		int imax = Xsize() - 1;
		int jmax = Ysize() - 1;
		for (int i = 0; i < Xsize(); i++) {
			if (carte[i][jmax] != ContenuCase.MUR)
				return false;
			if (carte[i][0] != ContenuCase.MUR)
				return false;
		}
		for (int j = 0; j < Ysize(); j++) {
			if (carte[0][j] != ContenuCase.MUR)
				return false;
			if (carte[imax][j] != ContenuCase.MUR)
				return false;
		}
		return true;
	}