public Tree<V, ?> tree() {
		return _tree;
	}
The node (tree), which has been matched by some pattern. This tree is the
argument of the {@link TreePattern#match(Tree)} call, in the case of a
match.

{@snippet lang="java":
final Tree<String, ?> tree = null; // @replace substring='null' replacement="..."
final TreePattern<String> pattern = null; // @replace substring='null' replacement="..."
final Optional<TreeMatchResult<String>> result = pattern.match(tree);
result.ifPresent(r -> {assert r.tree() == tree;});
}

@return node (tree), which has been matched by some pattern
jenetics.ext/src/main/java/io/jenetics/ext/rewriting/TreeMatchResult.java