[Puppet Users] Custom type, autoinclude

Hi,
I was thinking about a conceptual thing and I will try to explain with a
concrete example.

In the puppetlabs-lvm module
there is code like this in the logical_volume provider

if mount( '-f', '--guess-fstype', path) =~ /ext[34]/
resize2fs( path) || ...
end

The resize2fs command is in the e2fsprogs package (well it is more
complicated, but this is another topic), so this package has to be
installed or an error will thrown.

I was thinking about how to ensure that the package is installed.
I realize that I could do just

package { 'e2fsprogs': }
logical_volume { 'bla':
fs_type => 'ext3',
require => Package['e2fsprogs']
}

Is it possible to hide this dependency in the custom type?
Is it possible to include another class from within a custom type? After
the other class is included autorequire could do its job. I think it is
some kind of autoinclude that I am after.