add integration and blackbox test cases for margins and set_label
add integration and blackbox test cases for set_label_string and margins, fix bug in _base.py in line 1828
Merge branch 'master' of https://github.com/CSCD01/SUCH-TEAM-WOW
add integration and blackbox testing for set_label_string and margins, fix bug in _base.py in line 1828