def volume(self):
        """Box volume in m^3."""
        return (self.x2 - self.x1) * (self.y2 - self.y1) * (self.z2 - self.z1)
def volume(self):
        """Box volume in m^3."""
        return (self.x2 - self.x1) * (self.y2 - self.y1) * (self.z2 - self.z1)
Box volume in m^3.