(self)
return set([self])
Returns a set of queries that are *known* to be required to match
        for the entire query to match. Note that other queries might also turn
        out to be required but not be determinable by examining the static
        query.

        >>> a = Term("f", u"a")
        >>> b = Term("f", u"b")
        >>> And([a, b]).requires()
        set([Term("f", u"a"), Term("f", u"b")])
        >>> Or([a, b]).requires()
        set([])
        >>> AndMaybe(a, b).requires()
        set([Term("f", u"a")])
        >>> a.requires()
        set([Term("f", u"a")])
Returns a set of queries that are *known* to be required to match
        for the entire query to match. Note that other queries might also turn
        out to be required but not be determinable by examining the static
        query.
Returns a set of queries that are * known * to be required to match for the entire query to match . Note that other queries might also turn out to be required but not be determinable by examining the static query .
def requires(self):
        """Returns a set of queries that are *known* to be required to match
        for the entire query to match. Note that other queries might also turn
        out to be required but not be determinable by examining the static
        query.

        >>> a = Term("f", u"a")
        >>> b = Term("f", u"b")
        >>> And([a, b]).requires()
        set([Term("f", u"a"), Term("f", u"b")])
        >>> Or([a, b]).requires()
        set([])
        >>> AndMaybe(a, b).requires()
        set([Term("f", u"a")])
        >>> a.requires()
        set([Term("f", u"a")])
        """

        # Subclasses should implement the _add_required_to(qset) method

        return set([self])
def requires ( self ) : # Subclasses should implement the _add_required_to(qset) method return set ( [ self ] )