Make addSpan an instance method of TokenVisitor.

Since the callers are all inside `TokenVisitor` too, they no longer need to pass the `positionToToken` field.

PiperOrigin-RevId: 894319740

Author: eamonnmcmanus

core/src/main/java/com/google/googlejavaformat/java/javadoc/MarkdownPositions.java

@@ -81,21 +81,17 @@ private static class TokenVisitor {
     void visit(Node node) {
       boolean alreadyVisitedChildren = false;
       switch (node) {
-        case Heading heading ->
-            addSpan(positionToToken, heading, HEADER_OPEN_TOKEN, HEADER_CLOSE_TOKEN);
-        case Paragraph paragraph ->
-            addSpan(positionToToken, paragraph, PARAGRAPH_OPEN_TOKEN, PARAGRAPH_CLOSE_TOKEN);
-        case BulletList bulletList ->
-            addSpan(positionToToken, bulletList, LIST_OPEN_TOKEN, LIST_CLOSE_TOKEN);
-        case OrderedList orderedList ->
-            addSpan(positionToToken, orderedList, LIST_OPEN_TOKEN, LIST_CLOSE_TOKEN);
+        case Heading heading -> addSpan(heading, HEADER_OPEN_TOKEN, HEADER_CLOSE_TOKEN);
+        case Paragraph paragraph -> addSpan(paragraph, PARAGRAPH_OPEN_TOKEN, PARAGRAPH_CLOSE_TOKEN);
+        case BulletList bulletList -> addSpan(bulletList, LIST_OPEN_TOKEN, LIST_CLOSE_TOKEN);
+        case OrderedList orderedList -> addSpan(orderedList, LIST_OPEN_TOKEN, LIST_CLOSE_TOKEN);
         case ListItem listItem -> {
           int startPosition = listItem.getSourceSpans().getFirst().getInputIndex();
           Matcher matcher =
               LIST_ITEM_START_PATTERN.matcher(input).region(startPosition, input.length());
           verify(matcher.lookingAt());
           ListItemOpenTag openToken = new ListItemOpenTag(matcher.group(1));
-          addSpan(positionToToken, listItem, openToken, LIST_ITEM_CLOSE_TOKEN);
+          addSpan(listItem, openToken, LIST_ITEM_CLOSE_TOKEN);
           if (listItem.getFirstChild() instanceof Paragraph paragraph) {
             // A ListItem typically contains a Paragraph, but we don't want to visit that Paragraph
             // because that would lead us to introduce a line break after the list introduction
@@ -123,26 +119,25 @@ private void visitNodeList(Node node) {
         visit(node);
       }
     }
-  }
 
-  /**
-   * Adds tokens for the given node, {@code startToken} at the point where the node starts in the
-   * input, and {@code endToken} at the point where it ends. The {@code startToken} goes after any
-   * other tokens at that position and the {@code endToken} goes before any other tokens at that
-   * position. That reflects the structure. For example, at the start of a bullet list, the visitor
-   * we will translate this into {@link ListOpenTag} then {@link ListItemOpenTag} at the start
-   * position, and {@link ListItemCloseTag} then {@link ListCloseTag} (in that order) at the end
-   * position.
-   */
-  private static void addSpan(
-      ListMultimap<Integer, Token> positionToToken, Node node, Token startToken, Token endToken) {
-    // We could write the first part more simply as a `put`, but we do it this way for symmetry.
-    var first = node.getSourceSpans().getFirst();
-    int startPosition = first.getInputIndex();
-    positionToToken.get(startPosition).addLast(startToken);
-    var last = node.getSourceSpans().getLast();
-    int endPosition = last.getInputIndex() + last.getLength();
-    positionToToken.get(endPosition).addFirst(endToken);
+    /**
+     * Adds tokens for the given node, {@code startToken} at the point where the node starts in the
+     * input, and {@code endToken} at the point where it ends. The {@code startToken} goes after any
+     * other tokens at that position and the {@code endToken} goes before any other tokens at that
+     * position. That reflects the structure. For example, at the start of a bullet list, the
+     * visitor we will translate this into {@link ListOpenTag} then {@link ListItemOpenTag} at the
+     * start position, and {@link ListItemCloseTag} then {@link ListCloseTag} (in that order) at the
+     * end position.
+     */
+    private void addSpan(Node node, Token startToken, Token endToken) {
+      // We could write the first part more simply as a `put`, but we do it this way for symmetry.
+      var first = node.getSourceSpans().getFirst();
+      int startPosition = first.getInputIndex();
+      positionToToken.get(startPosition).addLast(startToken);
+      var last = node.getSourceSpans().getLast();
+      int endPosition = last.getInputIndex() + last.getLength();
+      positionToToken.get(endPosition).addFirst(endToken);
+    }
   }
 
   @Override