Parameters
        ----------
        module_name: String
            The analysis_path of the module
        class_name: String
            The analysis_path of the class
        attribute_name: String
            The analysis_path of the attribute

        Returns
        -------
        has_prior: bool
            True iff a prior exists for the module, class and attribute

def has(self, module_name, class_name, attribute_name):
        """
        Parameters
        ----------
        module_name: String
            The analysis_path of the module
        class_name: String
            The analysis_path of the class
        attribute_name: String
            The analysis_path of the attribute

        Returns
        -------
        has_prior: bool
            True iff a prior exists for the module, class and attribute
        """
        self.read(module_name)
        return self.parser.has_option(class_name, attribute_name)