anchor.diff:  %% @doc Inserts a document or multiple documents into a collection.
   %%      Returns the document or documents with an auto-generated _id if missing.
   
  -insert( Topology, Coll, Doc ) when is_tuple(Doc); is_map(Doc) ->
  +insert( Topology, Coll, Doc ) ->
   	case mc_topology:get_pool( Topology, [{rp_mode, primary}] ) of
   		{ ok, #{ pool := C } } ->
   			try	mongo:insert( C, Coll, Doc ) of
  
positive.code: 
  -include("mongo_protocol.hrl").
  
  -export([connect/3, disconnect/1, command/2, command/3, insert/3, update/4, delete/3, delete_one/3, find_one/3, find_one/4, find/4, find/3, count/3, count/4, count/5, ensure_index/3]).
  
  
  -type selector() :: bson:document().
  
negative.code: 
  %% @doc Replaces the document matching criteria entirely with the new Document.
  
  update( Topology, Coll, Selector, Doc ) ->
  	update( Topology, Coll, Selector, Doc, [] ).
  
  update( Topology, Coll, Selector, Doc, Options ) ->
  	case mc_topology:get_pool( Topology, [{rp_mode, primary}] ) of
  		{ ok, #{ pool := C } } ->
  			try	mongo:update( C, Coll, Selector, Doc, Options) of
  				R -> R
  			catch
  				error:not_master ->
  