Add a parameter which can be referenced.

        :param str param_id: identifier by which parameter may be referenced.
        :param str location: location of the parameter.
        :param dict component: parameter fields.
        :param dict kwargs: plugin-specific arguments

def parameter(self, component_id, location, component=None, **kwargs):
        """ Add a parameter which can be referenced.

        :param str param_id: identifier by which parameter may be referenced.
        :param str location: location of the parameter.
        :param dict component: parameter fields.
        :param dict kwargs: plugin-specific arguments
        """
        if component_id in self._parameters:
            raise DuplicateComponentNameError(
                'Another parameter with name "{}" is already registered.'.format(
                    component_id
                )
            )
        component = component or {}
        ret = component.copy()
        ret.setdefault("name", component_id)
        ret["in"] = location
        # Execute all helpers from plugins
        for plugin in self._plugins:
            try:
                ret.update(plugin.parameter_helper(component, **kwargs) or {})
            except PluginMethodNotImplementedError:
                continue
        self._parameters[component_id] = ret
        return self