code: def visit_CompilerDirectivesNode(self, node):
      directives = node.directives
      if "test_assert_path_exists" in directives:
          for path in directives["test_assert_path_exists"]:
              if TreePath.find_first(node, path) is None:
                  Errors.error(
                      node.pos,
                      "Expected path '%s' not found in result tree"
                      % path,
                  )
      if "test_fail_if_path_exists" in directives:
          for path in directives["test_fail_if_path_exists"]:
              if TreePath.find_first(node, path) is not None:
                  Errors.error(
                      node.pos,
                      "Unexpected path '%s' found in result tree"
                      % path,
                  )
      self.visitchildren(node)
      return node
  
imports: from __future__ import absolute_import
  import os
  import unittest
  import tempfile
  from .Compiler import Errors
  from .CodeWriter import CodeWriter
  from .Compiler.TreeFragment import TreeFragment, strip_common_indent
  from .Compiler.Visitor import TreeVisitor, VisitorTransform
  from .Compiler import TreePath
label_desc: Use image node_id 1 for calling the TreeAssertVisitor obj's underlying member method code with example usage: obj.visit_CompilerDirectivesNode(node) and returns: node