 constraint violation on the default path + addresses["home"].&lt;map key&gt;
 //i.e. a container element constraint violation for the map key
 context.buildConstraintViolationWithTemplate( "the map key is invalid" )
             .addPropertyNode( "addresses" )
             .addContainerElementNode( "&lt;map key&gt;", Map.class, 0 )
                 .inIterable().atKey( "invalid" )
             .addConstraintViolation();
 </pre>
 <p>
 Cross-parameter constraints on a method can create a node specific
 to a 