@Override
          protected boolean shouldKeep(StructForDelete<T> item) {
            return predicate.test(item);
          }
Get all delete ids of equality delete files

<p>For example, if there are two equality delete fields, one is [1, 2] and another is [1], the
delete ids will be [1, 2].

@return delete ids
amoro-format-iceberg/src/main/java/org/apache/amoro/io/reader/CombinedDeleteFilter.java