class_docstr: Parses compiler directives and converts them into AST annotations.
code: def _track_and_visit_loop(self, node):
      self.state[_LoopScope].enter()
      self.state[_LoopScope].ast_node = node
      node = self.generic_visit(node)
      # Edge case: a loop with just one directive statement would become empty.
      if not node.body:
          node.body = [gast.Pass()]
      self.state[_LoopScope].exit()
      return node
  
imports: import inspect
  import gast
  from nvidia.dali._autograph.core import converter
  from nvidia.dali._autograph.lang import directives
  from nvidia.dali._autograph.pyct import anno
label_desc: Use image node_id 8 for calling the DirectivesTransformer obj's underlying member method code with example usage: obj._track_and_visit_loop(node) and returns: node