presto-spi/src/main/java/io/prestosql/spi/block/VariableWidthBlockBuilder.java/VariableWidthBlockBuilder/entryAdded
class VariableWidthBlockBuilder:    private void entryAdded(int bytesWritten, boolean isNull)
    {
        if (!initialized) {
            initializeCapacity();
        }
        if (valueIsNull.length <= positions) {
            growCapacity();
        }

        valueIsNull[positions] = isNull;
        offsets[positions + 1] = sliceOutput.size();

        positions++;

        if (blockBuilderStatus != null) {
            blockBuilderStatus.addBytes(SIZE_OF_BYTE + SIZE_OF_INT + bytesWritten);
        }
    }