### Do not break existing code
-* keep working code working **at all times**. find ways to ensure that this is the case. examples include writing alternative classes that replace existing functionality and adding runtime optiobs to select between old and new code.
+* keep working code working **at all times**. find ways to ensure that this is the case. examples include writing alternative classes that replace existing functionality and adding runtime options to select between old and new code.
### Small commits with relevant commit message