Code39 constructor
Create a Code39 symbology with the default or required properties.
The arguments module
must be non-negative and greater than 0.
Since Code 39 is self-checking, it is not normally necessary to provide
a checksum.
However, in applications requiring an extremely high level of accuracy,
a modulo 43 checksum can be added,
if the enableCheckSum
is true.
Implementation
Code39({int? module, this.enableCheckSum = true}) : super(module: module);