Capabilty to add additionnal dependencies when running javadoc

While playing with with doclava, it looks this doclet in some case needs some dependencies which are not provided when running javadoc.
My use which fail : I depends on ehcache-core:2.4.2 which has provided dependency to javax.transaction:jta:1.1 .
So I propose to be able to add additionnal dependencies as :

<additionnalDependencies>
  <additionnalDependency>
    <groupId>geronimo-spec</groupId>
    <artifactId>geronimo-spec-jta</artifactId>
    <version>1.0.1B-rc4</version>
  </additionnalDependency>
</additionnalDependencies>

Those dependencies will be add in -classpath of javadoc cli.