Write a function called "getFirstElementOfProperty". Given an object and a key, "getFirstElementOfProperty" returns the first element of the array located at the given key.

getFirstElementOfProperty

 Notes:
* If the array is empty, it should return undefined.
* If the property at the given key is not an array, it should return undefined.
* If there is no property at the key, it should return undefined.
function getFirstElementOfProperty(obj, key) {
  // your code here
   if ( Array.isArray( obj[key] ) === false ){
      return undefined;
    }else if ( obj[key][0] === undefined){
      return undefined;
    }else{
      return obj[key][0];
    }
 
}