protected boolean shouldVisitNextChild(RuleNode node, T currentResult) {
		return true;
	}
This method is called after visiting each child in
{@link #visitChildren}. This method is first called before the first
child is visited; at that point {@code currentResult} will be the initial
value (in the default implementation, the initial value is returned by a
call to {@link #defaultResult}. This method is not called after the last
child is visited.

<p>The default implementation always returns {@code true}, indicating that
{@code visitChildren} should only return after all children are visited.
One reason to override this method is to provide a "short circuit"
evaluation option for situations where the result of visiting a single
child has the potential to determine the result of the visit operation as
a whole.</p>

@param node The {@link RuleNode} whose children are currently being
visited.
@param currentResult The current aggregate result of the children visited
to the current point.

@return {@code true} to continue visiting children. Otherwise return
{@code false} to stop visiting children and immediately return the
current aggregate result from {@link #visitChildren}.
runtime/Java/src/org/antlr/v4/runtime/tree/AbstractParseTreeVisitor.java