Conversion to a new_unit. Right now, only supports 1 to 1 mapping of
        units of each type.

        Args:
            new_unit: New unit type.

        Returns:
            A FloatWithUnit object in the new units.

        Example usage:
        >>> e = Energy(1.1, "eV")
        >>> e = Energy(1.1, "Ha")
        >>> e.to("eV")
        29.932522246 eV

def to(self, new_unit):
        """
        Conversion to a new_unit. Right now, only supports 1 to 1 mapping of
        units of each type.

        Args:
            new_unit: New unit type.

        Returns:
            A FloatWithUnit object in the new units.

        Example usage:
        >>> e = Energy(1.1, "eV")
        >>> e = Energy(1.1, "Ha")
        >>> e.to("eV")
        29.932522246 eV
        """
        return FloatWithUnit(
            self * self.unit.get_conversion_factor(new_unit),
            unit_type=self._unit_type,
            unit=new_unit)