Content of "NS_" section is lost on dbc->dbc conversion

[fpetry]

When converting or merging DBC files the content of the "NS_ :" section is lost:

canmatrix/src/canmatrix/formats/dbc.py

Line 174 in 16a6878

header = "VERSION \"created by canmatrix\"\n\n\nNS_ :\n\nBS_:\n\n"

I didn't find any reliable source what this Section exactly does (thank you well documented DBC format...). But I would assume that a DBC to DBC conversion should not change the content semantically.

Bonus question: Why is there a space between NS_ and the colon but not in all other sections? This seems to be not canmatrix specific but a general thing...

EDIT: "NS_ :" Seems to stand for "new symbols"