@Override
    public <T> Boolean isNull(BoundReference<T> ref) {
      // dictionaries only contain non-nulls and cannot eliminate based on isNull or NotNull
      return ROWS_MIGHT_MATCH;
    }
Test whether the dictionaries for a row group may contain records that match the expression.

@param fileSchema schema for the Parquet file
@param dictionaries a dictionary page read store
@return false if the file cannot contain rows that match the expression, true otherwise.
amoro-format-mixed/amoro-mixed-hive/src/main/java/org/apache/iceberg/parquet/AdaptHiveParquetDictionaryRowGroupFilter.java