def add_breadcrumb_to(name, url, trail_index)
      breadcrumb_trails
      @breadcrumb_trails[trail_index] ||= []
      @breadcrumb_trails[trail_index] << {
        name: case name
              when Proc then name.call(self)
              else name
              end,
        url:  case url
              when Proc then url.call(self)
              else url ? url_for(url) : nil
              end
      }
    end
def add_breadcrumb_to(name, url, trail_index)
      breadcrumb_trails
      @breadcrumb_trails[trail_index] ||= []
      @breadcrumb_trails[trail_index] << {
        name: case name
              when Proc then name.call(self)
              else name
              end,
        url:  case url
              when Proc then url.call(self)
              else url ? url_for(url) : nil
              end
      }
    end
Add a breadcrumb to breadcrumb trail.
 @param trail_index index of breadcrumb trail
 @example
   add_breadcrumb_to("level 1", "level 1 url", 0)