code: public Vector select(int[] indices) {
          int newLength = indices.length;
  
          if (newLength == 0) {
              fail("No elements selected.");
          }
  
          Vector result = blankOfLength(newLength);
  
          for (int i = 0; i < newLength; i++) {
              result.set(i, get(indices[i]));
          }
  
          return result;
      }
docs: Returns a new vector with the selected elements.
  
  @param indices the array of indices
  
  @return the new vector with the selected elements