[BUG] Can't use Set instead of List on Java generation ( Set is not imported )

Hello, i'm using the latest snapshot of openapi-generator ( 5.0.0-SNAPSHOT ).

Here is the maven plugin is use :

                        <execution>
                            <id>Generate Spring</id>
                            <goals>
                                <goal>generate</goal>
                            </goals>
                            <configuration>
                                <inputSpec>${project.basedir}/src/main/resources/swagger/api.yml</inputSpec>
                                <output>${project.build.directory}/generated-sources/openapi/java</output>
                                <generatorName>spring</generatorName>
                                <instantiationTypes>array=HashSet</instantiationTypes>
                                <typeMappings>array=Set</typeMappings>
                                <importMappings>Set=java.util.Set,HashSet=java.util.HashSet</importMappings>
                            </configuration>
                        </execution>

I tried <importMappings>Set=java.util.Set</importMappings> ( without HashSet ) too.
The code is referencing Set but doesn't import the class.

Reproduce the issue with the Maven plugin configuration in the report, using the spring generator, Set type mapping, and import mappings. Inspect the Java/Spring generator's type and import handling, then verify that generated code using Set includes java.util.Set and compiles successfully.