Dynamic Key Unmarshaling in JSON with Go

When working with JSON data, it can be challenging to unmarshal into a struct if one of the keys is dynamic and cannot be directly mapped to a field name in the struct. To address this, a practical solution can be found in Golang.

Given a defined struct:

type X struct {
  A string `json:"a_known_string"`
  B string `json:"b_known_string"`
}

And a sample JSON string:

{
  "any string": {
    "a_known_string": "some value",
    "b_known_string": "another value"
  }
}

To capture both the known and dynamic key in the JSON, a map can be utilized:

var m map[string]X
err := json.Unmarshal([]byte(jsnStr), &m)

This approach allows for the storage of multiple objects under a single dynamic key, providing flexibility in data handling.

An example playground can be found [here](https://play.golang.org/p/jh-GAlUEo7n).