The top-level program node.
retry ^^^^^
foo(*bar)
^^^^
def foo((bar, *baz)); end
^^^^
def foo(*); bar(*); end
^
A list of statements.
“foo” ^^^^^
Visit a string that is expressed using a <<~ heredoc.
super(foo) ^^^^^^^^^^
‘foo` ^^^^^
Visit a node that represents a number. We need to explicitly handle the unary - operator.