$ ./test2.sh
+ mkdir test_git
+ cd test_git
+ git init
Initialized empty Git repository in /tmp/test_git/.git/
+ touch a
+ git add a
+ git commit -a -m 'initial commit'
[master (root-commit) a89912d] initial commit
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 a
+ git checkout -b new_branch
Switched to a new branch 'new_branch'
+ echo test
+ git commit -a -m 'test changed'
[new_branch d2c4601] test changed
 1 file changed, 1 insertion(+)
+ git checkout master
Switched to branch 'master'
+ echo test2
+ git commit -a -m 'test changed'
[master 1945ab9] test changed
 1 file changed, 1 insertion(+)
+ git checkout new_branch
Switched to branch 'new_branch'
+ git branch
  master
* new_branch
+ cat a
test