Vcs commit with named graph override

'vcs commit using named graph' is only override?
For example, suppose you have the following triple:
test1.ttl (s1 p1 o1.), test2.ttl (s2 p2 o2.)
stardog vcs commit --add test1.ttl -m "t1 commit"-g "http: // graph" myDb
next,
stardog vcs commit --add test2.ttl -m "t2 commit"-g "http: // graph" myDb

This deletes the triple of test1.ttl from the graph.

Is there a way to commit without deleting the previous triples?