extend-behavior-mixer.js

function extend() {
  var consumer  = arguments[0];
  var providers = ([]).slice.call(arguments, 1);

  for (var a = 0; a < providers.length; a++) {
    var provider = providers[a];
    var except   = (provider['except'] || []);

    except.push('except');

    for (var property in provider) {
      if ((except.indexOf(property) < 0) && provider.hasOwnProperty(property)) {
        consumer[property] = provider[property];
      }
    }
  }

  return consumer;
}