# File lib/backports/tools/std_lib.rb, line 8
        def include?(feature)
          return true if @@our_loads[feature]
          # Assume backported features are Ruby libraries (i.e. not C)
          @loaded ||= $LOADED_FEATURES.group_by{|p| File.basename(p, ".rb")}
          if fullpaths = @loaded[File.basename(feature, ".rb")]
            fullpaths.any?{|fullpath|
              base_dir, = fullpath.partition("/#{feature}")
              $LOAD_PATH.include?(base_dir)
            }
          end
        end