setNull(String strColName);

// Check the value of Q3RESULTS input column.
if(isNull("Q3RESULTS")) {

     // Set the value of output column to null.
     setNull("RESULTS");
}

// Check the value of Q3RESULTS input column.
String strColName = "Q3RESULTS";
if(isNull(strColName)) {

     // Set the value of output column to null.
     setNull(strColName);
}