private void generateFieldSize(FieldSpec field,
                                   Versions possibleVersions,
                                   boolean tagged) {
        if (field.type().fixedLength().isPresent()) {
            generateFixedLengthFieldSize(field, tagged);
        } else {
            generateVariableLengthFieldSize(field, possibleVersions, tagged);
        }
    }
Generate the size calculator for a variable-length array element.
Array elements cannot be null.
generator/src/main/java/org/apache/kafka/message/MessageDataGenerator.java