code: public static <T> HashSet<T> optimizedHashSet(final int s, final float lf) {
          return new HashSet<T>(s, lf);
      }
docs: Returns a hash set of type {@code T} optimized to the specified capacity
  and load factor.
  <p>
  Use optimized hash sets when the capacity of a hash set is known to be
  greater than sixteen (the default initial capacity) and a load factor is
  desired to control resizing behavior. The hash set implementation will
  automatically adjust the size to the next nearest power of two.
  </p>
  
  @param <T> Formal type parameter
  @param s Initial hash set capacity
  @param lf Hash set load factor
  @return Hash set of type {@code T}