your working tree are temporarily stored to a staging area
called the "index" with 'git add'. A file can be
reverted back, only in the index but not in the working tree,
-to that of the last commit with `git reset HEAD -- <file>`,
+to that of the last commit with `git reset HEAD \-- <file>`,
which effectively reverts 'git add' and prevents the changes to
this file from participating in the next commit. After building
the state to be committed incrementally with these commands,