input: 
  from typing import Dict
  
  def extract_features(input_str: str) -> Dict:
      """Extract specific features from a JSON string and return them as a dictionary.
      
      >>> extract_features('{"id": 111, "title": "This is a sample title", "body": "This is a sample body text"}')
      {'id': 111, 'title': 'This is a sample title', 'body_len': 38}
      """
      import json
      data = json.loads(input_str)
      
      features = {
          "id": data["id"],
          "title": data["title"],
          "body_len": len(data["body"])
      }
      
      return features
  
output:     import json
      data = json.loads(input_str)
      
      features = {
          "id": data["id"],
          "title": data["title"],
          "body_len": len(data["body"])
      }
      
      return features