text: class PDXFinder {
  
      static switchButtonText(targetId) {
  
          const  text1 = "SHOW ABSTRACT";
          const text2 = "HIDE ABSTRACT";
  
          let targetElement = document.querySelector(`${targetId}`);
          let nowText = targetElement.innerHTML.trim();
          switch(nowText) {
              case text1:
                  targetElement.innerHTML  = text2;
                  break;
              case text2:
                  targetElement.innerHTML  = text1;
                  break;
              default:
          }
      }
  
  }
  
  