public static @Nullable ASTNode prevLeaf(@Nullable ASTNode start, boolean expandChameleons) {
    while (start != null) {
      for (ASTNode each = start.getTreePrev(); each != null; each = each.getTreePrev()) {
        ASTNode leaf = findLastLeaf(each, expandChameleons);
        if (leaf != null) return leaf;
      }
      start = start.getTreeParent();
    }
    return null;
  }
public static @Nullable ASTNode prevLeaf(@Nullable ASTNode start, boolean expandChameleons)