Bug when used an object with a function and a variable with a function and destructuring

https://runkit.com/leobastiani/javascript-serialize-bug-variable-function-destructuring

Try the following code:
```javascript
const serialize = require("javascript-serialize"); // version 1.6.1
const obj = {
  someKey() {
    const someVariable = ({ someParam }) => {};
  },
};
serialize(obj);
```

and get: `{ "someKey": "someKey() { ...`