docs: private static Predicate join(final String joinWord, final List<Predicate> preds) {
          return new Predicate() {
              public void init(AbstractSqlCreator creator) {
                  for (Predicate p : preds) {
                      p.init(creator);
                  }
              }
              public String toSql() {
                  StringBuilder sb = new StringBuilder()
                  .append("(");
                  boolean first = true;
                  for (Predicate p : preds) {
                      if (!first) {
                          sb.append(" ").append(joinWord).append(" ");
                      }
                      sb.append(p.toSql());
                      first = false;
                  }
                  return sb.append(")").toString();
              }
          };
      }