code: function Array_includes(searchElement, // @arg Any
                          position) {    // @arg Integer = 0
                                         // @ret Boolean
      position = position || 0;
      var iz = this.length;
  
      if (iz === 0) {
          return false;
      }
  
      var i = 0;
  
      if (position >= 0) {
          i = position;
      } else {
          i = position + iz;
          if (i < 0) {
              i = 0;
          }
      }
  
      if (searchElement === searchElement) {
          for (; i < iz; ++i) {
              if (this[i] === searchElement) {
                  return true;
              }
          }
      } else if (isNaN(searchElement)) {
          for (; i < iz; ++i) {
              if (isNaN(this[i])) {
                  return true;
              }
          }
      } else { // maybe Symble, ... etc
          throw TypeError("Unsupported type");
      }
      return false;
  }
docs: === Array ===============================================