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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 add_config(self, slot, config_id, config_type, value):
 """Add a config variable assignment to this sensor graph. Args: slot (SlotIdentifier):
 The slot identifier that this config variable is assigned to. config_id (int):
 The 16-bit id of this config_id config_type (str):
 The type of the config variable, currently supported are fixed width integer types, strings and binary blobs. value (str|int|bytes):
 The value to assign to the config variable. """


        if slot not in self.config_database:
            self.config_database[slot] = {}

        self.config_database[slot][config_id] = (config_type, value)