1.6.x

[hashmapybx]

Key Improvements

1. Code Structure Optimization
   Splitting the complex testTwoLevelList() method into multiple, clear private methods
   Extracting duplicate logic from writeAndValidate() into a separate method
2. Enhanced Exception Handling
   Each method has clear exception handling and detailed error messages
   Using throw new IOException(..., e) to preserve the original exception stack trace
   Adding contextual information such as file paths to facilitate debugging
3. Improved Readability
   Adding detailed JavaDoc comments to explain each method's functionality
   Using meaningful variable names ( expectedIter , actualIter )
   Adding assertion messages ( as("Expected more rows at index %d", i) )
4. Resource Management Improvements
   A separate createTempFile() method now handles file creation failures
   Using a finally block in writeTestDataToParquet() to ensure writer closure
   Each try-with-resources block has clear exception handling
5. New Methods
   validateTwoLevelListConversion() - Validates two-level list conversion
   writeTestDataToParquet() - Writes test data
   readAndValidateTwoLevelList() - Read and validate a two-level list
   writeRecordsToParquet() - Write records
   readAndValidateRecords() - Read and validate records
   createTempFile() - Create a temporary file

[nastra]

@hashmapybx did you mean to open this PR against Iceberg's main branch? It seems like the code is partially specific to Flink 1.17, which isn't maintained anymore