说明：  Artistic Style is a reindenter and reformatter of C, C++, C# and Java source code. When indenting source code, we as programmers have a tendency to use both spaces and tab characters to create the wanted indentation. Moreover, some editors by default insert spaces instead of tabs when pressing the tab key, and other editors (Emacs for example) have the ability to "pretty up" lines by automatically setting up the white space before the code on the line, possibly inserting spaces in a code that up to now used only tabs for indentation.