LighterAST () { LighterAST lighterAST = getUserData(LIGHTER_AST_NODE_KEY); if (lighterAST == null) { FileASTNode node = getPsiFile().getNode(); lighterAST = myLighterASTShouldBeThreadSafe ? new TreeBackedLighterAST(node) : node.getLighterAST(); putUserData(LIGHTER_AST_NODE_KEY, lighterAST); } return lighterAST; }