code: public Stream<AbstractAttribute> buildAllAttributesStream(
              final boolean parallel) {
          final Stream<AbstractAttribute> attributesStream = buildAllTagsStream(
                  parallel).filter(tag -> tag.getAttributes() != null)
                          .map(tag -> {
                              return tag.getAttributes();
                          }).flatMap(attributes -> attributes.stream());
          return attributesStream;
      }
docs: Finds all attributes as stream from all tags.
  
  @param parallel
  true to internally use parallel stream. If true it
  will split the finding task to different batches and
  will execute the batches in different threads in
  parallel consuming all CPUs. It will perform faster
  in finding from extremely large number of tags but at
  the same time it will less efficient in finding from
  small number of tags.
  @return the stream of all attributes
  @since 3.0.0
  @author WFF