Require the mapper attribute

diff --git a/lib/LaTeX/TikZ/Meta/TypeConstraint/Autocoerce.pm b/lib/LaTeX/TikZ/Meta/TypeConstraint/Autocoerce.pm
index cdbc69c083c71a60cd759e7019a45bba4e137e45..36efdf19e6e54e91ecb7f90e47e3f268927d1082 100644 (file)
--- a/lib/LaTeX/TikZ/Meta/TypeConstraint/Autocoerce.pm
+++ b/lib/LaTeX/TikZ/Meta/TypeConstraint/Autocoerce.pm
@@ -34,8 +34,9 @@ It is called with the type constraint object as first argument, followed by the
 =cut
 
 has 'mapper' => (
- is  => 'ro',
- isa => 'CodeRef',
+ is       => 'ro',
+ isa      => 'CodeRef',
+ required => 1,
 );
 
 =head2 C<parent>