WIP: First steps in refactoring to aggregate fetching

libraries/shared/watcher.go

@@ -1,6 +1,7 @@
 package shared
 
 import (
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/vulcanize/vulcanizedb/pkg/core"
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
 	"github.com/vulcanize/vulcanizedb/pkg/transformers/shared"
@@ -14,15 +15,22 @@ type Watcher struct {
 
 func (watcher *Watcher) AddTransformers(us []shared.TransformerInitializer) {
 	for _, transformerInitializer := range us {
-		transformer := transformerInitializer(&watcher.DB, watcher.Blockchain)
+		transformer := transformerInitializer(&watcher.DB)
 		watcher.Transformers = append(watcher.Transformers, transformer)
 	}
 }
 
 func (watcher *Watcher) Execute() error {
+	// TODO Solve checkedHeadersColumn issue
+	// TODO Handle start and end numbers in transformers?
+	var missingHeaders []core.Header
+
+	// TODO Get contract addresses and topic0s
+	var logs []types.Log
+
 	var err error
 	for _, transformer := range watcher.Transformers {
-		err = transformer.Execute()
+		err = transformer.Execute(logs, missingHeaders)
 	}
 	return err
 }