Add DSL for P&F stage
Example DSL:
stage Timestampfilter extends X implements Y,Z
in ITimestampable inputPort
out ITimestampable inBounds
out ITimestampable outBounds
param long minTimestamp
param long maxTimestamp
execute
obj <= inputPort
if (obj) {
if (obj.timestamp < minTimestamp or maxTimestamp < obj.timestamp) {
obj => outBounds
} else {
obj => inBounds
}
}