Wrote write goroutine functions.

Refactored subpackages back to root package.

neo4j.go

@@ -0,0 +1,42 @@
+package heartwood
+
+import (
+	"context"
+	"github.com/neo4j/neo4j-go-driver/v6/neo4j"
+)
+
+// Interface
+
+type GraphDB interface {
+	MergeSubgraph(ctx context.Context, subgraph *BatchSubgraph) ([]neo4j.ResultSummary, error)
+}
+
+func NewGraphDriver(driver neo4j.Driver) GraphDB {
+	return &graphdb{driver: driver}
+}
+
+type graphdb struct {
+	driver neo4j.Driver
+}
+
+func (n *graphdb) MergeSubgraph(ctx context.Context, subgraph *BatchSubgraph) ([]neo4j.ResultSummary, error) {
+	return MergeSubgraph(ctx, n.driver, subgraph)
+}
+
+// Functions
+
+func ConnectNeo4j(ctx context.Context, uri, user, password string) (neo4j.Driver, error) {
+	driver, err := neo4j.NewDriver(
+		uri,
+		neo4j.BasicAuth(user, password, ""))
+	if err != nil {
+		return nil, err
+	}
+
+	err = driver.VerifyConnectivity(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	return driver, nil
+}