assert_nil(CHISE::IDS_Tree.new("⿳士冖匕").check_integrity)
assert_raise(RuntimeError, "unmatch leaves") { check_tree("⿳士冖") }
assert_raise(RuntimeError, "extra nodes") { check_tree("⿳士冖匕匕") }
assert_nil(CHISE::IDS_Tree.new("⿳士冖匕").check_integrity)
assert_raise(RuntimeError, "unmatch leaves") { check_tree("⿳士冖") }
assert_raise(RuntimeError, "extra nodes") { check_tree("⿳士冖匕匕") }