split out WorkbookRelationships

Author: SimonCropp

src/DeterministicIoPackaging/DeterministicPackage.cs

@@ -38,7 +38,7 @@ static void DuplicateEntry(Entry sourceEntry, Archive targetArchive)
             return;
         }
 
-        if (IsWorkbookRelationships(sourceEntry))
+        if (sourceEntry.IsWorkbookRelationships())
         {
             var xml = PatchRelationships(sourceStream, false);
             SaveXml(xml, targetStream);
@@ -72,7 +72,7 @@ static async Task DuplicateEntryAsync(Entry sourceEntry, Archive targetArchive,
             return;
         }
 
-        if (IsWorkbookRelationships(sourceEntry))
+        if (sourceEntry.IsWorkbookRelationships())
         {
             var xml = PatchRelationships(sourceStream, false);
             await SaveXml(xml, targetStream, cancel);
@@ -157,8 +157,4 @@ static bool IsPsmdcp(Entry entry) =>
 
     static bool IsRelationships(Entry _) =>
         _.FullName is "_rels/.rels";
-
-    static bool IsWorkbookRelationships(Entry _) =>
-        _.FullName is "xl/_rels/workbook.xml.rels";
-
 }

src/DeterministicIoPackaging/WorkbookRelationships.cs

@@ -0,0 +1,5 @@
+static class WorkbookRelationships
+{
+    public static bool IsWorkbookRelationships(this ZipArchiveEntry entry) =>
+        entry.FullName is "xl/_rels/workbook.xml.rels";
+}