How to Get NonWorkingDays from an issue in jira 7.6.0?

[Cristian Pérez González]

I am developing a plugin for jira 7.6.0 and I have to obtain the NonWorkingDays having as parameter

 ApplicationUser userIssue

And as a result this

Set<NonWorkingDay> nonWorkingDays

I also have to use greenhopper. Right now I am using this dependency.

<dependency>
   <groupId>com.atlassian.jira.plugins</groupId>
   <artifactId>jira-greenhopper-plugin</artifactId>
   <version>7.6.0-DAILY20171103151351</version>
   <scope>provided</scope>
</dependency>

How could I get them?

Note1:

My plugin is not able to see WorkingDaysManager and throws me the exception NoClassDefFoundError

Note2:

If I use this dependency. 

<dependency>
   <groupId>com.atlassian.jira.plugins</groupId>
   <artifactId>jira-greenhopper-plugin</artifactId>
   <version>6.1.1</version>
   <scope>provided</scope>
</dependency>

My plugin is not able to see the GreenHopper class and throws me the exception NoClassDefFoundError