@staticmethod
def _check_contains_key(file, dictionary, key):
    """
        :param str file: The reference file, which to give in the error message
        :param dict dictionary: the dict to check the key's existance
        :param str key: the key to check for 
        :raises ValueError
        
        Checks if a dict originating from a certain file contains a certain key and raises an exception otherwise
        """
    if key not in dictionary:
        raise ValueError(
            'Could not find %s in %s, record folder seems not to be valid!' %
            (key, file))
