https://docs.spring.io/spring-data/mongodb/reference/api/java/org/springframework/data/mongodb/core/aggregation/StringOperators.StringOperatorFactory.html
StringOperators.StringOperatorFactory (Spring Data MongoDB - Core 5.0.5 API)
declaration: package: org.springframework.data.mongodb.core.aggregation, class: StringOperators, class: StringOperatorFactory
spring data mongodbcoreapi