libclass-contract-perl 1.14-8 (amd64 binary) in ubuntu trusty

 The Class::Contract module implements strong encapsulation, static
 inheritance, and design-by-contract condition checking for object-oriented
 Perl. The module provides a declarative syntax for attribute, method,
 constructor, and destructor definitions at both the object and class level.
 Pre-conditions, post-conditions, and class invariants are also fully
 supported.