<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def make_code(self):
 """This method returns the best possible QR code."""

        from copy import deepcopy

        #Get the size of the underlying matrix
        matrix_size = tables.version_size[self.version]

        #Create a template matrix we will build the codes with
        row = [' ' for x in range(matrix_size)]
        template = [deepcopy(row) for x in range(matrix_size)]

        #Add mandatory information to the template
        self.add_detection_pattern(template)
        self.add_position_pattern(template)
        self.add_version_pattern(template)

        #Create the various types of masks of the template
        self.masks = self.make_masks(template)

        self.best_mask = self.choose_best_mask()
        self.code = self.masks[self.best_mask]