Strategy start/end dates have a weird dual setup. You can choose to
use the campaign dates or set custom ones. If the former, you cannot
post custom start-end dates, and so Strategy.save removes those from
the body. However, if you are changing a strategy from having start/end
dates to using campaign start/end dates, you are supposed to POST a
null value. So we need to convert the None to an empty string.
Add removal for ChildPixel. This enables removal of a piggybacked pixel from a container.
Strategy.saveremoves those from the body. However, if you are changing a strategy from having start/end dates to using campaign start/end dates, you are supposed to POST a null value. So we need to convert the None to an empty string.ChildPixel. This enables removal of a piggybacked pixel from a container.