protected <T> T getValueFromJson(String json, String propName) throws IOException {
        return (T) jsonStringToMap(json).get(propName);
    }
protected < T > T getValueFromJson ( String json , String propName ) throws IOException { return ( T ) jsonStringToMap ( json ) . get ( propName ) ; }
A helper method that takes a json string and extracts the value of the specified
property.

@param json     the json string
@param propName the name of the property to extract
@param <T>      The type for the value expected to be returned.
@return the value of the specified property
@throws IOException