```ruby
require 'redmine_charts/line_data_converter'
require 'redmine_charts/pie_data_converter'
require 'redmine_charts/stack_data_converter'
require 'redmine_charts/utils'
require 'redmine_charts/conditions_utils'
require 'redmine_charts/grouping_utils'
require 'redmine_charts/range_utils'
require 'redmine_charts/issue_patch'
require 'redmine_charts/time_entry_patch'

module RedmineCharts

  def self.has_sub_issues_functionality_active
    (Redmine::VERSION.to_a <=> [0,9,4,'devel']) >= 0
  end

end```

Check if current version of Redmine supports subissues
user
```ruby
require 'redmine_charts/line_data_converter'
require 'redmine_charts/pie_data_converter'
require 'redmine_charts/stack_data_converter'
require 'redmine_charts/utils'
require 'redmine_charts/conditions_utils'
require 'redmine_charts/grouping_utils'
require 'redmine_charts/range_utils'
require 'redmine_charts/issue_patch'
require 'redmine_charts/time_entry_patch'

module RedmineCharts

  def self.has_sub_issues_functionality_active
    ((Redmine::VERSION.to_a <=> [0,9,5]) >= 0) or (Redmine::VERSION.to_a == [0,9,4,'devel'])
  end

end```
assistant