'extract column names from tablehead'

def process_line(self, line):

    line = line.split('%')[0]
    line = line.replace('\\tablehead', '')
    line = line.strip()
    if ((line[0] == '{') and (line[(-1)] == '}')):
        line = line[1:(-1)]
    else:
        raise core.InconsistentTableError('\\tablehead    is    missing    {}')
    return line.replace('\\colhead', '')
