combining XMLEvent lists

Hello,

I've got an Iterator with Lists (Java) out of XMLEvents, which are
serialized fragments like:

  <page>
    <id>732819</id>
    <title>blubb</title>
    <revision>
      <id>233192</id>
      <timestamp>2000-01-21T02:12:21Z</timestamp>
      <text>blaaaaa</text>
    </revision>
  </page>

I want to find combine Lists which have the same page id and the same
revision timestamp, for example:

List 1:
  <page>
    <id>732819</id>
    <title>blubb</title>
    <revision>
      <id>233192</id>
      <timestamp>2000-01-21T02:12:21Z</timestamp>
      <text>blaaaaa</text>
    </revision>
  </page>

List 2:
  <page>
    <id>732819</id>
    <title>blubb</title>
    <revision>
      <id>333345</id>
      <timestamp>2000-01-21T02:12:21Z</timestamp>
      <text>foobar</text>
    </revision>
  </page>

List 3:
  <page>
    <id>732819</id>
    <title>blubb</title>
    <revision>
      <id>333345</id>
      <timestamp>2000-02-23T03:12:21Z</timestamp>
      <text>baz</text>
    </revision>
  </page>

should become Lists of XMLEvents, which are serialized as

Final List 1:
  <page>
    <id>732819</id>
    <title>blubb</title>
    <revision>
      <id>233192</id>
      <timestamp>2000-01-21T02:12:21Z</timestamp>
      <text>blaaaaa</text>
    </revision>
    <revision>
      <id>333345</id>
      <timestamp>2000-01-21T02:12:21Z</timestamp>
      <text>foobar</text>
    </revision>
  </page>

Final List 2:
  <page>
    <id>732819</id>
    <title>blubb</title>
    <revision>
      <id>333345</id>
      <timestamp>2000-02-23T03:12:21Z</timestamp>
      <text>baz</text>
    </revision>
  </page>

I want to work with the Lists itself, but I don't think XPath-Parsers
are capable of processing something like a List of XMLEvents.

regards,
Johannes