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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 deploy_token_contract( self, token_supply: int, token_decimals: int, token_name: str, token_symbol: str, token_type: str = 'CustomToken', ):
 """Deploy a token contract."""

        receipt = self.deploy(
            contract_name=token_type,
            args=[token_supply, token_decimals, token_name, token_symbol],
        )
        token_address = receipt['contractAddress']
        assert token_address and is_address(token_address)
        token_address = to_checksum_address(token_address)
        return {token_type: token_address}