docs: def text_length(elem):
      """Returns length of the content in this element.
  
      Return value is not correct but it is **good enough***.
      """
  
      if not elem:
          return 0
  
      value = elem.value()
  
      try:
          value = len(value)
      except:
          value = 0
  
      try:
          for a in elem.elements:
              value += len(a.value())
      except:
          pass
  
      return value