s2 := new(big.Int).Mul(y2, z1)
	s2.Mul(s2, z1z1)
	s2.Mod(s2, curve.P)
	r := new(big.Int).Sub(s2, s1)
	if r.Sign() == -1 {
		r.Add(r, curve.P)
	}
	yEqual := r.Sign() == 0
	if xEqual && yEqual {
		return curve.doubleJacobian(x1, y1, z1)
	}
	r.Lsh(r, 1)
	v := new(big.Int).Mul(u1, i)

	x3.Set(r)
	x3.Mul(x3, x3)
	x3.Sub(x3, j)
	x3.Sub(x3, v)
	x3.Sub(x3, v)
	x3.Mod(x3, curve.P)

Matthew Dempsky <******@****.***> 1646087539 -0800

	if !_Equal(s3, s3) {
		panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s3, s3))
	}

	if _Equal(s1, nil) {
		panic(fmt.Sprintf("_Equal(%v, nil) = true, want false", s1))
	}
	if _Equal(nil, s1) {
		panic(fmt.Sprintf("_Equal(nil, %v) = true, want false", s1))
	}
	if !_Equal(s1[:0], nil) {
		panic(fmt.Sprintf("_Equal(%v, nil = false, want true", s1[:0]))
	}
}

func offByOne[Elem Integer](a, b Elem) bool {

	}
}

func TestEqual() {
	if !_Equal(m1, m1) {
		panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", m1, m1))
	}
	if _Equal(m1, nil) {
		panic(fmt.Sprintf("_Equal(%v, nil) = true, want false", m1))
	}
	if _Equal(nil, m1) {
		panic(fmt.Sprintf("_Equal(nil, %v) = true, want false", m1))
	}
	if !_Equal[int, int](nil, nil) {
		panic("_Equal(nil, nil) = false, want true")
	}

}

func TestEqual() {
	s1 := _Make[string]()
	s2 := _Make[string]()
	if !_Equal(s1, s2) {
		panic(fmt.Sprintf("_Equal(%v, %v) = false, want true", s1, s2))
	}
	s1.Add("hello")
	s1.Add("world")
	if got := s1.Len(); got != 2 {
		panic(fmt.Sprintf("(%v).Len() == %d, want 2", s1, got))
	}
	if _Equal(s1, s2) {
		panic(fmt.Sprintf("_Equal(%v, %v) = true, want false", s1, s2))
	}
}

func TestCopy() {

    /** Returns the value from the right map (possibly null). */
    @ParametricNullness
    V rightValue();

    /**
     * Two instances are considered equal if their {@link #leftValue()} values are equal and their
     * {@link #rightValue()} values are also equal.
     */
    @Override
    boolean equals(@CheckForNull Object other);

    /**

  private Objects() {}

  /**
   * Determines whether two possibly-null objects are equal. Returns:
   *
   * <ul>
   *   <li>{@code true} if {@code a} and {@code b} are both null.
   *   <li>{@code true} if {@code a} and {@code b} are both non-null and they are equal according to
   *       {@link Object#equals(Object)}.
   *   <li>{@code false} in all other situations.
   * </ul>
   *

    /** Returns the value from the right map (possibly null). */
    @ParametricNullness
    V rightValue();

    /**
     * Two instances are considered equal if their {@link #leftValue()} values are equal and their
     * {@link #rightValue()} values are also equal.
     */
    @Override
    boolean equals(@CheckForNull Object other);

    /**

  private Objects() {}

  /**
   * Determines whether two possibly-null objects are equal. Returns:
   *
   * <ul>
   *   <li>{@code true} if {@code a} and {@code b} are both null.
   *   <li>{@code true} if {@code a} and {@code b} are both non-null and they are equal according to
   *       {@link Object#equals(Object)}.
   *   <li>{@code false} in all other situations.
   * </ul>
   *

  }

  @Override
  public boolean equals(@CheckForNull Object object) {
    if (object instanceof Entry) {
      Entry<?, ?> that = (Entry<?, ?>) object;
      return Objects.equal(this.getKey(), that.getKey())
          && Objects.equal(this.getValue(), that.getValue());
    }
    return false;
  }

  @Override
  public int hashCode() {
    K k = getKey();
    V v = getValue();