def _get_min_indent(lines, tab_width=4):
    """Find the minimum count of indenting whitespaces in lines.

    Arguments:
        lines (tuple):
            The content to search the minimum indention for.
        tab_width (int):
            The number of spaces expand tabs before searching for indention by.
    """
    min_indent = 2**32
    for line in lines:
        i = 0
        for c in line:
            if c == ' ':
                i += 1
            elif c == '\t':
                i += tab_width - (i % tab_width)
            else:
                break

        if min_indent > i:
            min_indent = i
        if not min_indent:
            break
    return min_indent