private static void doAddColumns(PriorityQueue<Add> adds, UpdateSchema us) {
    while (!adds.isEmpty()) {
      Add add = adds.poll();
      if (StringUtils.isBlank(add.parent)) {
        us.addColumn(add.field, add.type, add.doc);
      } else {
        if (add.parent.contains(DOT)) {
          LOG.error("field: {}", add);
          throw new UnsupportedOperationException(
              "do not support add deeper than two nested field");
        }
        us.addColumn(add.parent, add.field, add.type, add.doc);
      }
    }
  }
Apply the pending changes to the original schema and returns the result.

<p>This does not result in a permanent update.

@return the result Schema when all pending updates are applied
amoro-format-iceberg/src/main/java/org/apache/amoro/op/KeyedSchemaUpdate.java