<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def open(self):
 """ Obtains the lvm and vg_t handle. Usually you would never need to use this method unless you are doing operations using the ctypes function wrappers in conversion.py *Raises:* * HandleError """

        if not self.handle:
            self.lvm.open()
            self.__vgh = lvm_vg_open(self.lvm.handle, self.name, self.mode)
            if not bool(self.__vgh):
                raise HandleError("Failed to initialize VG Handle.")