code: private JMFType findTupleChildByName(JSTuple tup, String name) {
      for (int i = 0; i < tup.getFieldCount(); i++) {
        JMFType theField = getEffectiveType(tup.getField(i));
        String fieldName = theField.getFeatureName();
        if (fieldName != null && fieldName.equals(name))
          return theField;
      }
      return null;
    }
docs: Find the child of a tuple by name