code: function optimizeNestedIifes(node) {
    var ok =
      matches({
        type: "ReturnStatement",
        argument: {
          type: "CallExpression",
          callee: {
            type: "FunctionExpression",
            body: {}
          }
        }
      })(node) &&
      get(node, "argument.arguments.length") === 0 &&
      get(node, "argument.callee.params.length") === 0 &&
      get(node, "argument.callee.body.body.length") === 1 &&
      get(node, "argument.callee.body.body[0].type") === "ReturnStatement";
    if (ok) {
      var kidNode = node.argument.callee.body.body[0];
      estraverse.replace(kidNode, {enter: optimizeNestedIifes});
      return kidNode;
    }
  }
docs: Turns `return (function() { return EXPR }())` into `return EXPR`