Perl module for building tree structures using PerlSAX handlers

 The XML::Handler::Trees module provides three PerlSAX handler classes for
 building tree structures. XML::Handler::Tree builds the same type of tree
 as the "Tree" style in XML::Parser. XML::Handler::EasyTree builds the same
 type of tree as the "EasyTree" style added to XML::Parser by
 XML::Parser::EasyTree. XML::Handler::TreeBuilder builds the same
 type of tree as Sean M. Burke's XML::TreeBuilder. These classes make
 it possible to construct these tree structures from sources other
 than XML::Parser.
 .
 All three handlers can be driven by either PerlSAX 1 or PerlSAX 2
 drivers. In all cases, the end_document() method returns a reference
 to the constructed tree, which normally becomes the return value of
 the PerlSAX driver.