Creating a new OperatorChain

HelaAmr

Hello,

I am implementing a new OperatorChain and i want to add operators to it.
I added this code to its constructor:

ExampleSetGenerator expGenOperator = OperatorService.createOperator(ExampleSetGenerator .class);
getSubprocess(0).addOperator(expGenOperator );

but when i added this operator to the main frame with dragging action i found that two inner operators were created inside it.
Note: i am working with Rapid Miner 5.1
I hope that you could help me to understand this problem and solve it.

Best regards,