def configure_project
      say "Configuring #{self.project.path.basename}"

      group = self.project["Seeds"]
      if group
        group.clear
      else
        uuid = Xcodeproj::uuid_with_name "Seeds"
        group = self.project.new_group_with_uuid("Seeds", uuid)
      end

      # remove existing group that doesn't have any file references
      group.groups.each do |seedgroup|
        valid_files = seedgroup.children.select do |child|
          File.exist?(child.real_path)
        end
        if valid_files.length == 0
          seedgroup.remove_from_project
        end
      end

      self.source_files.each do |seedname, filepaths|
        uuid = Xcodeproj::uuid_with_name "Seeds/#{seedname}"
        seedgroup = group[seedname] ||
                    group.new_group_with_uuid(seedname, uuid)
        filepaths.each do |path|
          filename = path.split('/')[-1]
          relpath = path[self.root_path.length..-1]
          uuid = Xcodeproj::uuid_with_name relpath
          file_reference = seedgroup[filename] ||
                           seedgroup.new_reference_with_uuid(path, uuid)
          self.file_references << file_reference
        end

        unusing_files = seedgroup.files - self.file_references
        unusing_files.each { |file| file.remove_from_project }
      end
    end
def configure_project
      say "Configuring #{self.project.path.basename}"

      group = self.project["Seeds"]
      if group
        group.clear
      else
        uuid = Xcodeproj::uuid_with_name "Seeds"
        group = self.project.new_group_with_uuid("Seeds", uuid)
      end

      # remove existing group that doesn't have any file references
      group.groups.each do |seedgroup|
        valid_files = seedgroup.children.select do |child|
          File.exist?(child.real_path)
        end
        if valid_files.length == 0
          seedgroup.remove_from_project
        end
      end

      self.source_files.each do |seedname, filepaths|
        uuid = Xcodeproj::uuid_with_name "Seeds/#{seedname}"
        seedgroup = group[seedname] ||
                    group.new_group_with_uuid(seedname, uuid)
        filepaths.each do |path|
          filename = path.split('/')[-1]
          relpath = path[self.root_path.length..-1]
          uuid = Xcodeproj::uuid_with_name relpath
          file_reference = seedgroup[filename] ||
                           seedgroup.new_reference_with_uuid(path, uuid)
          self.file_references << file_reference
        end

        unusing_files = seedgroup.files - self.file_references
        unusing_files.each { |file| file.remove_from_project }
      end
    end
Adds source files to the group 'Seeds' and save its reference to
 {#file_references} and removes disused sources files,

 @see #file_references

 @!visibility private