@classmethod<EOL><INDENT>def set_shared_config(cls, config):<DEDENT>
assert isinstance(config, dict)<EOL>cls._sharedInstance.config.update(config)<EOL>if cls._sharedInstance.instance:<EOL><INDENT>cls._sharedInstance.instance = None<EOL><DEDENT>
This allows to set a config that will be used when calling
            ``shared_blockchain_instance`` and allows to define the configuration
            without requiring to actually create an instance