presto-spi/src/main/java/io/prestosql/spi/block/VariableWidthBlockBuilder.java/VariableWidthBlockBuilder/getRetainedSizeInBytes
class VariableWidthBlockBuilder:    @Override
    public long getRetainedSizeInBytes()
    {
        long size = INSTANCE_SIZE + sliceOutput.getRetainedSize() + arraysRetainedSizeInBytes;
        if (blockBuilderStatus != null) {
            size += BlockBuilderStatus.INSTANCE_SIZE;
        }
        return size;
    }