1 files changed, 17 insertions, 6 deletions
diff --git a/src/main/java/org/zwobble/mammoth/internal/styles/StyleMap.java b/src/main/java/org/zwobble/mammoth/internal/styles/StyleMap.java
index 7d28bf1..b181074 100644
--- a/src/main/java/org/zwobble/mammoth/internal/styles/StyleMap.java
+++ b/src/main/java/org/zwobble/mammoth/internal/styles/StyleMap.java
@@ -3,6 +3,8 @@ package org.zwobble.mammoth.internal.styles;
 import com.google.common.collect.Iterables;
 import org.zwobble.mammoth.internal.documents.Paragraph;
 import org.zwobble.mammoth.internal.documents.Run;
+import org.zwobble.mammoth.internal.util.MammothLists;
+import org.zwobble.mammoth.internal.util.MammothOptionals;
 
 import java.util.List;
 import java.util.Optional;
@@ -14,14 +16,14 @@ public class StyleMap {
 
     public static final StyleMap EMPTY = new StyleMapBuilder().build();
 
-    private final HtmlPath underline;
-    private final HtmlPath strikethrough;
+    private final Optional<HtmlPath> underline;
+    private final Optional<HtmlPath> strikethrough;
     private final List<StyleMapping<Paragraph>> paragraphStyles;
     private final List<StyleMapping<Run>> runStyles;
 
     public StyleMap(
-        HtmlPath underline,
-        HtmlPath strikethrough,
+        Optional<HtmlPath> underline,
+        Optional<HtmlPath> strikethrough,
         List<StyleMapping<Paragraph>> paragraphStyles,
         List<StyleMapping<Run>> runStyles)
     {
@@ -31,11 +33,20 @@ public class StyleMap {
         this.runStyles = runStyles;
     }
 
-    public HtmlPath getUnderline() {
+    public StyleMap update(StyleMap styleMap) {
+        // TODO: add appropriate tests
+        return new StyleMap(
+            MammothOptionals.first(styleMap.underline, underline),
+            MammothOptionals.first(styleMap.strikethrough, strikethrough),
+            MammothLists.concat(styleMap.paragraphStyles, paragraphStyles),
+            MammothLists.concat(styleMap.runStyles, runStyles));
+    }
+
+    public Optional<HtmlPath> getUnderline() {
         return underline;
     }
 
-    public HtmlPath getStrikethrough() {
+    public Optional<HtmlPath> getStrikethrough() {
         return strikethrough;
     }