Errors:
test/Test73.java:6:
  Semantic Error: attributes can only be introduced in AST nodes
test/Test73.java:7:
  Semantic Error: attributes can only be introduced in AST nodes
test/Test73.java:8:
  Semantic Error: only subclasses of ASTNode can be rewritten
test/Test73.java:11:
  Semantic Error: root node must be an AST node
test/Test73.java:11:
  Semantic Error: attributes can only be introduced in AST nodes