a factory method for producing a conditional QueryFilter with an AndOp
a factory method for producing a RelationalFilter with an EqOp
a factory method for producing a RelationalFilter with a GtOp
a factory method for producing a RelationalFilter with a LteOp
a factory method for producing a RelationalFilter with a LtOp
a factory method for producing a RelationalFilter with a LteOp
a factory method for producing a RelationalFilter with an NeqOp
a factory method for producing a conditional QueryFilter with an OrOp
query filter factory methods