How to create instance of IRecordSet

I need to create instance of

com.sapportals.connector.execution.structures.IRecordSet

I need to fillup importTable when proceeding BAPI call

Now i'm doing it this way:

MappedRecord output = (MappedRecord) ix.execute(ixspec, input);

Object inTable = output.get("REQUISITION_ITEMS");

((IRecordSet)inTable).insertRow();

((IRecordSet)inTable).setString("DOC_TYPE","NB");

input.put("REQUISITION_ITEMS", ((IRecordSet)inTable));

output = (MappedRecord) ix.execute(ixspec, input);

I'm calling 'ix.execute(ixspec, input)' twice

First time just to get instance of IRecordSet inTable

and second time for executing BAPI call

I think there must be better way to get that instance

Please help