code: protected void preamble(SB sb, int subtree) throws RuntimeException {
      String subt = subtree > 0 ? "_" + String.valueOf(subtree) : "";
      sb.p("class ").p(_javaClassName).p(subt).p(" {").nl().ii(1);
      sb.ip("static final double score0").p("(double[] data) {").nl().ii(1); // predict method for one tree
      sb.ip("double pred = ");
    }
docs: code preamble