def check_and_setup_parameters(self):
        """Check whether parameters lack a source of daa.

        In case there's no source of data for one or more parameters,
        we raise a LackOfInputError explaining the situation.
        """
        ### create a list to hold names of parameters lacking a data source
        lacking_data_source = []

        ### iterate over each parameter, performing
        ### checks and acting according to their results

        for input_socket in self.input_sockets:

            if not hasattr(input_socket, 'parent'):
                lacking_data_source.append(input_socket.parameter_name)

        ### if parameters lacking data sources are found,
        ### raise LackOfInputError

        if lacking_data_source:
            raise LackOfInputError(self, lacking_data_source)
Check whether parameters lack a source of daa.

        In case there's no source of data for one or more parameters,
        we raise a LackOfInputError explaining the situation.
        
nodezator/graphman/operatornode/execution.py