private void addColumn()

in cassandra-four-zero-bridge/src/main/java/org/apache/cassandra/cdc/msg/FourZeroCdcEventBuilder.java [197:249]
48 lines of code
7 McCabe index (conditional complexity)

    private void addColumn(List<Value> holder, ColumnData cd)
    {
        ColumnMetadata columnMetadata = cd.column();
        String columnName = columnMetadata.name.toCQLString();
        if (columnMetadata.isComplex()) // multi-cell column
        {
            ComplexColumnData complex = (ComplexColumnData) cd;
            DeletionTime deletionTime = complex.complexDeletion();
            if (deletionTime.isLive())
            {
                // the complex data is live, but there could be element deletion inside.
                if (complex.column().type instanceof ListType)
                {
                    // In the case of unfrozen lists, it reads the value from C*
                    readFromCassandra(holder, complex);
                }
                else
                {
                    processComplexData(holder, complex);
                }
            }
            else if (complex.cellsCount() > 0)
            {
                // The condition, complex data is not live && cellCount > 0, indicates that a new value is set to the column.
                // The CQL operation could be either insert or update the column.
                // Since the new value is in the mutation already, reading from C* can be skipped
                processComplexData(holder, complex);
            }
            else // the entire multi-cell collection/UDT is deleted.
            {
                kind = CdcEvent.Kind.DELETE;
                updateMaxTimestamp(deletionTime.markedForDeleteAt());
                holder.add(makeValue(null, complex.column()));
            }
        }
        else // simple column
        {
            Cell<?> cell = (Cell<?>) cd;
            updateMaxTimestamp(cell.timestamp());
            if (cell.isTombstone())
            {
                holder.add(makeValue(null, cell.column()));
            }
            else
            {
                holder.add(makeValue(cell.buffer(), cell.column()));
                if (cell.isExpiring())
                {
                    setTTL(cell.ttl(), cell.localDeletionTime());
                }
            }
        }
    }