The trigger is called as a method, and receives the new value as its argument.
The trigger is called I<after> the value is set.
-This differs from an after method modifier in two ways. First, a
+This differs from an C<after> method modifier in two ways. First, a
trigger is only called when the attribute is set, as opposed to
whenever the accessor method is called (for reading or
writing). Second, it is also called when an attribute's value is
=head2 Delegation
-Attributes can define methods which simply delegate to their values:
+An attribute can define methods which simply delegate to its value:
has 'hair_color' => (
is => 'ro',