text: (function array() {
      let object = {
          last() {
              return this[this.length - 1];
          },
          skip(n) {
              return this.slice(n);
          },
          take(n) {
              return this.slice(0, n);
          },
          sum() {
              return this.reduce((a, c) => {
                  return a + c;
              }, 0);
  
          },
          average() {
              return this.sum() / this.length
          }
      };
  
      Object.assign(Array.prototype, object);
  })();
  
  let array = [5, 1, 2, 5];
  
  console.log(array.sum());
  console.log(array.average());