    # File temp/parsers/baseparser.rb, line 395
          def normalize( input, entities=nil, entity_filter=nil )
            copy = input.clone
            # Doing it like this rather than in a loop improves the speed
            copy.gsub!( EREFERENCE, '&amp;' )
            entities.each do |key, value|
              copy.gsub!( value, "&#{key};" ) unless entity_filter and
                                          entity_filter.include?(entity)
            end if entities
            copy.gsub!( EREFERENCE, '&amp;' )
            DEFAULT_ENTITIES.each do |key, value|
              copy.gsub!( value[3], value[1] )
            end
            copy
          end