docs: String createButtonHtml(SocialLoginConfig config) {
          if (config == null) {
              return "";
          }
          String uniqueId = config.getUniqueId();
          String displayName = config.getDisplayName();
          String buttonValue = WebUtils.htmlEncode(getObscuredConfigId(uniqueId));
  
          StringBuilder buttonHtml = new StringBuilder();
          buttonHtml.append("<button type=\"submit\" ");
          buttonHtml.append("class=\"" + HTML_CLASS_BUTTON + " " + HTML_CLASS_MEDIUM + "\" ");
          buttonHtml.append("value=\"" + buttonValue + "\" ");
          buttonHtml.append("onclick=\"" + createCookieFunctionName + "(" + buttonValue + ")\" ");
          buttonHtml.append(">");
          if (displayName == null) {
              if (tc.isDebugEnabled()) {
                  Tr.debug(tc, "displayName was not configured for this config, will use the id attribute instead");
              }
              displayName = uniqueId;
          }
          buttonHtml.append(WebUtils.htmlEncode(displayName));
          buttonHtml.append("</button>\n");
          return buttonHtml.toString();
      }