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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def quartus_tcl_add_interface(self, buff, thisIntf, packager):
 """ Create interface in Quartus TCL :return: add_interface command string """

        if packager.getInterfaceDirection(thisIntf) == INTF_DIRECTION.MASTER:
            dir_ = "start"
        else:
            dir_ = "end"

        name = packager.getInterfaceLogicalName(thisIntf)
        buff.extend(["add_interface %s %s %s" % 
                     (name, self.get_quartus_name(), dir_)])

        self.quartus_prop(buff, name, "ENABLED", True)
        self.quartus_prop(buff, name, "EXPORT_OF", "")
        self.quartus_prop(buff, name, "PORT_NAME_MAP", "")
        self.quartus_prop(buff, name, "CMSIS_SVD_VARIABLES", "")
        self.quartus_prop(buff, name, "SVD_ADDRESS_GROUP", "")