     leaf = @encache @createLeaf -(@nextAddress++)
     @splice root, 0, 0, leaf.address
     # Write the root branch.
-    @rewriteBranch root, ".replace", _
+    @writeBranch root, ".replace", _
     @rewriteLeaf leaf, ".replace", _
     @replace leaf, ".replace", _
     @replace root, ".replace", _

  # until place using `replace`.

  #
  rewriteBranch: (page, suffix, _) ->
    filename = @filename page.address, suffix
    record = [ page.right, page.addresses ]
    json = JSON.stringify(record)


    @io.size -= child.right.page.size

    @io.writeBranch child.left.page, "replace", _

    child.right.page.addresses.length = 0
    @io.writeBranch child.right.page, "unlink", _

    if parent.isPivot
      right = pivot.page
