code: public double get(long i) {
          if (i < 0 || i >= idxAfterLast) {
              return missingEntries;
          }
          return elements[SafeCast.safeLongToInt(i)];
      }
docs: Gets the i'th entry in the vector.
  @param i The index of the element to get.
  @return The value of the element to get.