in src/js/utils/RuleExporter.js [183:194]
static createJSONFromRuleProperties(
properties: ?Immutable.Map<string, RuleProperty>
): ?{ [string]: RulePropertyJSON } {
if (properties != null) {
return properties
.filter(property => RulePropertyUtils.isValid(property))
.map(property => this.createJSONFromRuleProperty(property))
.filter(Boolean)
.toJSON();
}
return null;
}