public void collectRewriteDataFiles(Map<DataFile, List<ContentFile<?>>> collector) {
      collector.putAll(rewriteDataFiles);
      if (left != null) {
        left.collectRewriteDataFiles(collector);
      }
      if (right != null) {
        right.collectRewriteDataFiles(collector);
      }
    }
split file tree with split condition.

@param collector - collect result
@param canSplit - if this tree can split
amoro-format-iceberg/src/main/java/org/apache/amoro/optimizing/plan/MixedIcebergPartitionPlan.java