Add edges to existing graph

[siyuan0322]

Add edges to existing graph.

[codecov-io]

Codecov Report

Merging #222 (5166a9b) into main (a749f90) will decrease coverage by 7.79%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #222      +/-   ##
==========================================
- Coverage   75.37%   67.57%   -7.80%     
==========================================
  Files          55       55              
  Lines        4459     4463       +4     
==========================================
- Hits         3361     3016     -345     
- Misses       1098     1447     +349     

Impacted Files	Coverage Δ
src/client/ds/i_object.h	90.00% <100.00%> (ø)
src/server/services/meta_service.cc	62.50% <0.00%> (-20.11%)	⬇️
src/server/server/vineyard_server.cc	58.05% <0.00%> (-17.86%)	⬇️
src/server/memory/stream_store.cc	49.56% <0.00%> (-16.23%)	⬇️
src/server/server/vineyard_server.h	85.71% <0.00%> (-14.29%)	⬇️
src/server/util/etcd_launcher.cc	65.68% <0.00%> (-13.41%)	⬇️
src/server/async/socket_server.cc	59.80% <0.00%> (-12.17%)	⬇️
src/server/util/meta_tree.cc	65.04% <0.00%> (-12.04%)	⬇️
src/server/services/etcd_meta_service.h	80.00% <0.00%> (-12.00%)	⬇️
src/server/services/meta_service.h	66.58% <0.00%> (-11.78%)	⬇️
... and 5 more

[sighingnow]

LGTM. Before merging, please test it against the graphscope repo to make sure everything works.

[siyuan0322]

@sighingnow Why has the coverage dropped so much?

[sighingnow]

codecov.io is a liar :)