Give blank (empty) lines the same indent level as the preceding line.

    Args:
        indent_texts: An iterable of tuples each containing an integer in the
            first element and a string in the second element.

    Returns:
        A list of tuples each containing an integer in the first element and a
        string in the second element.

def pad_blank_lines(indent_texts):
    '''Give blank (empty) lines the same indent level as the preceding line.

    Args:
        indent_texts: An iterable of tuples each containing an integer in the
            first element and a string in the second element.

    Returns:
        A list of tuples each containing an integer in the first element and a
        string in the second element.
    '''
    current_indent = 0
    result = []
    for indent, text in indent_texts:
        if len(text) > 0:
            current_indent = indent
        result.append((current_indent, text))
    return result