def METHOD_NAME(line, used, from_end):
    available_lines = MAX_ERROR_LINES // 2 - used
    available_chars = available_lines * _MAX_ERROR_LINE_LENGTH - 3
    if len(line) > available_chars:
        if not from_end:
            line = line[:available_chars] + '...'
        else:
            line = '...' + line[-available_chars:]
    return line