def write_meta_header(filename, meta_dict):
header = '<STR_LIT>'<EOL>for tag in MHD_TAGS:<EOL><INDENT>if tag in meta_dict.keys():<EOL><INDENT>header += '<STR_LIT>'.format(tag, meta_dict[tag])<EOL><DEDENT><DEDENT>with open(filename, '<STR_LIT:w>') as f:<EOL><INDENT>f.write(header)<EOL><DEDENT>
Write the content of the `meta_dict` into `filename`.

    Parameters
    ----------
    filename: str
        Path to the output file

    meta_dict: dict
        Dictionary with the fields of the metadata .mhd file