has model => (is => 'ro', isa => IM_Object, required => 1);
has fields => (is => 'ro', isa => 'ArrayRef', lazy_build => 1);
- has field_args => (is => 'ro');
+ has field_args => (is => 'rw');
has field_order => (is => 'ro', isa => 'ArrayRef');
has builder_cache => (is => 'ro', isa => 'HashRef', lazy_build => 1);