def write_collections
      edge_collections.flat_map do |target_state|
        [target_state.edge_collection_name] +
          (target_state.from_vertices + target_state.to_vertices).map(&:collection)
      end.uniq.compact
    end
def write_collections
      edge_collections.flat_map do |target_state|
        [target_state.edge_collection_name] +
          (target_state.from_vertices + target_state.to_vertices).map(&:collection)
      end.uniq.compact
    end
A list of collections we will write to

 @return [Array<String>] A list of the collection names we will write to