Validate searchspace content, 
       if the searchspace file is not json format or its values does not contain _type and _value which must be specified, 
       it will not be a valid searchspace file

def validate_search_space_content(experiment_config):
    '''Validate searchspace content, 
       if the searchspace file is not json format or its values does not contain _type and _value which must be specified, 
       it will not be a valid searchspace file'''
    try:
        search_space_content = json.load(open(experiment_config.get('searchSpacePath'), 'r'))
        for value in search_space_content.values():
            if not value.get('_type') or not value.get('_value'):
                print_error('please use _type and _value to specify searchspace!')
                exit(1)
    except:
        print_error('searchspace file is not a valid json format!')
        exit(1)