def scope_chain(scope, chain)
      if scope.scope_method
        chain.public_send scope.scope_method
      elsif scope.scope_block
        instance_exec chain, &scope.scope_block
      else
        chain
      end
    end
def scope_chain(scope, chain)
      if scope.scope_method
        chain.public_send scope.scope_method
      elsif scope.scope_block
        instance_exec chain, &scope.scope_block
      else
        chain
      end
    end
Scope an ActiveRecord::Relation chain

 Example:
   scope_chain(Scope.new(:published), Article)
   # => Article.published

 @param scope The <ActiveAdmin::Scope> we want to scope on
 @param chain The ActiveRecord::Relation chain or ActiveRecord::Base class to scope
 @return <ActiveRecord::Relation or ActiveRecord::Base> The scoped relation chain