text: export function unique(arr) {
      let results = [];
      for (let item of arr) {
          if (results.indexOf(item) == -1) {
              results.push(item);
          }
      }
      return results;
  }
  
  export function unique1(arr) {
      let results = [];
      let hash = new Map();
      for (let item of arr) {
          if (!hash.get(item)) {
              results.push(item);
              hash.set(item, true);
          }
      }
      return results;
  }
  