public static PsiReference[] extractFromContentAttribute(final XmlAttributeValue value) {
    boolean hasNonStandardTokens =
      ContainerUtil.exists(value.getChildren(), ch -> !ATTRIBUTE_VALUE_STD_TOKENS.contains(ch.getNode().getElementType()));
    if (hasNonStandardTokens) return PsiReference.EMPTY_ARRAY;
    String text = value.getValue();
    int start = text.indexOf(CHARSET_PREFIX);
    if (start != -1) {
      start += CHARSET_PREFIX.length();
      int end = text.indexOf(';', start);
      if (end == -1) end = text.length();
      String charsetName = text.substring(start, end);
      TextRange textRange = new TextRange(start, end).shiftRight(xmlAttributeValueRange(value).getStartOffset());
      return new PsiReference[]{new XmlEncodingReference(value, charsetName, textRange, 0)};
    }
    return PsiReference.EMPTY_ARRAY;
  }
public static PsiReference[] extractFromContentAttribute(final XmlAttributeValue value)