code: public Vector midpoint(Vector other) {
          x = (x + other.x) / 2;
          y = (y + other.y) / 2;
          z = (z + other.z) / 2;
          return this;
      }
docs: Sets this vector to the midpoint between this vector and another.
  
  @param other The other vector
  @return this same vector (now a midpoint)