presto-main/src/main/java/io/prestosql/util/JsonUtil.java/ArrayBlockBuilderAppender/append
class ArrayBlockBuilderAppender:        @Override
        public void append(JsonParser parser, BlockBuilder blockBuilder)
                throws IOException
        {
            if (parser.getCurrentToken() == JsonToken.VALUE_NULL) {
                blockBuilder.appendNull();
                return;
            }

            if (parser.getCurrentToken() != START_ARRAY) {
                throw new JsonCastException(format("Expected a json array, but got %s", parser.getText()));
            }
            BlockBuilder entryBuilder = blockBuilder.beginBlockEntry();
            while (parser.nextToken() != END_ARRAY) {
                elementAppender.append(parser, entryBuilder);
            }
            blockBuilder.closeEntry();
        }