<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def init_config_json(config_file):
 """Deserializes a JSON configuration file. Args: config_file (str):
 The path to the JSON file. Returns: dict: A dictionary object containing the JSON data. If ``config_file`` does not exist, returns ``None``. """

    json_data = None
    try:
        if os.path.exists(config_file):
        #Load the config file

            with open(config_file) as json_file:
                json_data = json.load(json_file)
                return unicode_convert(json_data)
        else:
            return None
    except:
        line, filename, synerror = trace()
        raise ArcRestHelperError({
                    "function": "init_config_json",
                    "line": line,
                    "filename":  filename,
                    "synerror": synerror,
                                    }
                                    )
    finally:
        json_data = None

        del json_data

        gc.collect()