Javaparser comment expression

I'm trying to comment all calls to a custom method inside a java file using Javaparser. My first approach is to use a ModifierVisitor:

ModifierVisitor<Object> visitante = new ModifierVisitor<Object>() {

            @Override
            public Visitable visit(MethodCallExpr n, Object arg) {
                if (!"MYMETHOD".equalsIgnoreCase(n.getNameAsString())) {
                    return super.visit(n, arg);
                }
                Node comment = new BlockComment(n.toString());
                return comment;
            }
        };
        visitante.visit(this.ficheroCompilado, null);

... the code finds the method calls to "MYMETHOD" correctly, but when I try to replace it with a BlockComment, an exception is thrown:

java.lang.ClassCastException: com.github.javaparser.ast.comments.LineComment cannot be cast to com.github.javaparser.ast.expr.Expression
    at com.github.javaparser.ast.visitor.ModifierVisitor.visit(ModifierVisitor.java:477)
    at com.github.javaparser.ast.visitor.ModifierVisitor.visit(ModifierVisitor.java:51)
    at com.github.javaparser.ast.stmt.ExpressionStmt.accept(ExpressionStmt.java:71)


...

It seems I can only replace an Expression by another Expression (because the change is inside an ExpressionStmt).

How could I about it and convert the method call to a comment?

Thank you all

Updated: Finally, I've made a hack: changing the name of the method to "//" + method name, so it ends up commented.

Finally, I've made a hack: changing the name of the method to "//" + method name, so it ends up commented.