Extract HasGetChildren from HasChildren for better safety

Author: mwilliamson

src/main/java/org/zwobble/mammoth/internal/conversion/RawText.java

@@ -27,8 +27,8 @@ public static String extractRawText(DocumentElement node) {
         } else if (node instanceof Tab) {
             return "\t";
         } else {
-            List<DocumentElement> children = tryCast(HasChildren.class, node)
-                .map(HasChildren::getChildren)
+            List<DocumentElement> children = tryCast(HasGetChildren.class, node)
+                .map(HasGetChildren::getChildren)
                 .orElse(list());
             String suffix = tryCast(Paragraph.class, node).map(paragraph -> "\n\n").orElse("");
             return extractRawText(children) + suffix;

src/main/java/org/zwobble/mammoth/internal/documents/HasChildren.java

@@ -2,7 +2,6 @@
 
 import java.util.List;
 
-public interface HasChildren<T> {
-    List<DocumentElement> getChildren();
+public interface HasChildren<T> extends HasGetChildren {
     T replaceChildren(List<DocumentElement> newChildren);
 }

src/main/java/org/zwobble/mammoth/internal/documents/HasGetChildren.java

@@ -0,0 +1,7 @@
+package org.zwobble.mammoth.internal.documents;
+
+import java.util.List;
+
+public interface HasGetChildren {
+    List<DocumentElement> getChildren();
+}