code: private void parseAttribute(final Attributes atts) {
          URI target = toURI(atts.getValue(ATTRIBUTE_NAME_COPY_TO));
          if (target == null) {
              return;
          }
          final String attrScope = atts.getValue(ATTRIBUTE_NAME_SCOPE);
  
          // external resource is filtered here.
          if (ATTR_SCOPE_VALUE_EXTERNAL.equals(attrScope) || ATTR_SCOPE_VALUE_PEER.equals(attrScope)
                  // FIXME: testing for :// here is incorrect, rely on source scope instead
                  || target.toString().contains(COLON_DOUBLE_SLASH) || target.toString().startsWith(SHARP)) {
              return;
          }
  
          final URI targetAbs = stripFragment(target.isAbsolute() ? target : currentFile.resolve(target));
          assert targetAbs.isAbsolute();
  
          final String attrFormat = getFormat(atts);
  
          if (isFormatDita(attrFormat)) {
              final URI source = toURI(atts.getValue(ATTRIBUTE_NAME_HREF));
              if (source != null) {
                  if (source.toString().isEmpty()) {
                      logger.warn("Copy-to task [href=\"\" copy-to=\"" + targetAbs + "\"] was ignored.");
                  } else {
                      final URI sourceAbs = stripFragment(currentFile.resolve(source));
                      assert sourceAbs.isAbsolute();
                      final URI copyToSourceAbs = copyToMap.get(targetAbs);
                      if (copyToSourceAbs != null) {
                          if (!sourceAbs.equals(copyToSourceAbs)) {
                              logger.warn(MessageUtils.getMessage("DOTX065W", source.toString(), targetAbs.toString()).toString());
                          }
                      } else if (atts.getValue(ATTRIBUTE_NAME_CHUNK) != null &&
                              atts.getValue(ATTRIBUTE_NAME_CHUNK).contains(CHUNK_TO_CONTENT)) {
                          // Ignore
                      } else {
                          copyToMap.put(targetAbs, sourceAbs);
                      }
                  }
              }
          }
      }
docs: Parse the input attributes for needed information.
  
  @param atts all attributes