docs: def split_date(value):
      """
          This method splits a date in a tuple.
          value: valid iso date
  
          ex:
          2016-01-31: ('2016','01','01')
          2016-01: ('2016','01','')
          2016: ('2016','','')
      """
      if not is_valid_date(value):
          return ('', '', '')
  
      splited = value.split('-')
  
      try:
          year = splited[0]
      except IndexError:
          year = ''
  
      try:
          month = splited[1]
      except IndexError:
          month = ''
  
      try:
          day = splited[2]
      except IndexError:
          day = ''
  
      return (year, month, day)