Validating on object fits a implemenation

gistfile1.txt

Object.prototype.NAMESPACEvalidate = function(validator) {
  validator(this);
  return this;
}

isValid = function(item) {
  if(typeof item.coolMethod !== 'function') {
    throw("not a valid item, missing coolMethod");
  } 
}
doFunStuffWithItems(item) {
  return item.NAMESPACEvalidate(isValid).coolMethod("baseball")
}