ActiveRecord.establish_connection uses class variable instead of accessor method

Is there a reason ActiveRecord.establish_connection uses @@connection_handler.establish_connection instead of connection_handler.establish_connection? I'm trying to make a subclass of ActiveRecord::Base that has it's own ConnectionHandler instance and I would want to leave ActiveRecord::Base's connection handler exactly the same. Here is what I'm trying to do:

class AnotherActiveRecord < ActiveRecord::Base
  @@another_connection_handler = ActiveRecord::ConnectionAdapters::ConnectionHandler.new
  def connection_handler
    @@another_connection_handler
  end
end

Would it be possible for establish_connection to use connection_handler accessor method so that this overloading can be done easier? Or is there a better way to do this?

Thanks!