private OptionPreset getOptionPreset() {
        if (this.options != null && this.options.preset != null) {
            return this.options.preset.getPreset();
        }
        this.getLog().debug("- No 'options/preset' configured. Applying default: PLAIN_JSON");
        return OptionPreset.PLAIN_JSON;
    }
Determine the standard option preset of the generator. Take it from the configuration or set the default. The default is: PLAIN_JSON

@return The OptionPreset
jsonschema-maven-plugin/src/main/java/com/github/victools/jsonschema/plugin/maven/SchemaGeneratorMojo.java