code: public static long dotProduct3(
      final long x0,
      final long y0,
      final long z0,
      final long x1,
      final long y1,
      final long z1)
    {
      final long x = x0 * x1;
      final long y = y0 * y1;
      final long z = z0 * z1;
      return x + y + z;
    }
docs: Calculate the dot product of
  {@code (x0, y0, z0)} and {@code (x1, y1, z1)}.
  
  @param x0 The X component of the first vector
  @param y0 The Y component of the first vector
  @param z0 The Z component of the first vector
  @param x1 The X component of the second vector
  @param y1 The Y component of the second vector
  @param z1 The Z component of the second vector
  
  @return The dot product