code: public String getValue(String key) throws IOException {
      JsonParser p = this.getParser();
      JsonToken t;
  
      t = p.nextToken();
  
      while (t != null) {
        if (t == JsonToken.FIELD_NAME && p.getCurrentName().equals(key)) {
          String value = p.nextTextValue();
          p.close();
          return value;
        }
        t = p.nextToken();
      }
      p.close();
      return null;
    }
docs: Return a value from the component.
  <p>
  <strong>NOTE:</strong>Use this for values only, not to retrieve
  subcomponents. Use class specific methods to retrieve subcompnents.
  <p>
  Retrieve a value from the current component. If {@code key} is not
  found, return {@code null}.
  
  @param key key to lookup in the component.
  @return a String value for this component.
  @throws IOException if there is an I/O error