code: def valid_token(token):
      
      is_scale = False
  
      # Check if the token represents a scale
      # If it doesn't set a flag accordingly
      try:
          Scale(token)
          is_scale = True
      except ScaleFormatError:
          pass
  
      # If token either represents a numerical value, a
      # separator token, or a scale, it is considered valid
      if any([token.isdigit(), token in SEPARATOR_TOKENS, is_scale]):
          return True
  
      return False
docs: Asserts a provided string is a valid duration token representation
  
      :param  token: duration representation token
      :type   token: string