@staticmethod
def _normalize_header(raw_headers_list):
    """Lower-case all header strings and replace periods with underscores.

        Args:
            raw_headers_list (List[str]): A list of the headers from the Annovar txt output file.

        Returns:
            List[str]: A list of the normalized headers, in the same order as the input list.
        """
    normalized_headers_list = []
    for curr_header in raw_headers_list:
        normalized_headers_list.append(curr_header.lower().replace('.', '_'))
    return normalized_headers_list
