code: @Override
      public final void visitElement(Element element) {
          newlineAndIndent();
          if (isWriting()){
              beginTag(element.getName()); // "<elementName"
              isClosed = false;
          }
      }
docs: While the static blocks are not in cache then it appends elements to
  the main StringBuilder or PrintStream.
  Once already cached then it does nothing.
  This method appends the String {@code "<elementName"} and it leaves the element
  open to include additional attributes.
  Before that it may close the parent begin tag with {@code ">"} if it is
  still opened (!isClosed).
  The newlineAndIndent() is responsible for this job to check whether the parent element
  is still opened or not.
  
  @param element