I'm getting an error "Found multiple extensions which provide method originPullRequestDiscoveryTrait with arguments []: [[com.cloudbees.jenkins.plugins.bitbucket.OriginPullRequestDiscoveryTrait" when I try to use the originPullRequestDiscoveryTrait.  

I think it could be fixed by adding the @Symbol to OriginPullRequestDiscoveryTrait.java.]  That's what was done for BranchDiscoveryTrait.java.

job-dsl usage

organizationFolder('Org') {
   organizations {
     github {
       repoOwner('Owner')
       traits {
            originPullRequestDiscoveryTrait()
              }

        }

   }
}

Stacktrace...

javaposse.jobdsl.dsl.DslException: Found multiple extensions which provide method originPullRequestDiscoveryTrait with arguments []: [[com.cloudbees.jenkins.plugins.bitbucket.OriginPullRequestDiscoveryTrait, org.jenkinsci.plugins.github_branch_source.OriginPullRequestDiscoveryTrait]]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:83)
at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteNoUnwrapNoCoerce.callConstructor(ConstructorSite.java:105)