'Extend the resource filter of a particular component, does
not affect the master resource filter (as opposed to add_filter)
@param alias: the alias of the component
@param f: a Query or a S3ResourceQuery instance'

def add_component_filter(self, alias, f=None):

    if (f is None):
        return
    if (self.rfilter is None):
        self.rfilter = S3ResourceFilter(self)
    self.rfilter.add_filter(f, component=alias, master=False)
