title: Moose trigger caller
body: <p>Is there any way of knowing the trigger caller attribute in Moose ?</p>
  
  <p>For example, taking the example from Moose::Manual::Attributes:</p>
  
  <pre><code>has 'size' =&gt; (
    is      =&gt; 'rw',
    trigger =&gt; \&amp;_size_set,
  );
  
  sub _size_set {
    my ( $self, $size, $old_size ) = @_;
  
    my $msg = $self-&gt;name;
  
    if ( @_ &gt; 2 ) {
        $msg .= " - old size was $old_size";
    }
  
    $msg .= " - size is now $size";
    warn $msg;
  }
  </code></pre>
  
  <p>Is it possible in <strong>_set_size</strong> to know that the attribute <strong>size</strong> called it, without needing to specify the name of the caller attribute explicitly?</p>
  
  <p><strong>EDIT</strong>: updated per comment.</p>