text: function augment(destination, source, methodNames) {
    if (methodNames) {
      for (var methodName of methodNames) {
  	  if (source.hasOwnProperty(methodName)) {
          destination[methodName] = source[methodName];
        }
      }
    } else {
      for (var methodName in source) {
        if (source.hasOwnProperty(methodName)) {
          destination[methodName] = source[methodName];
        }
      }  
    }
  
    return destination; 
  }
  