old_contents: from utils import CanadianJurisdiction
  
  
  class Alberta(CanadianJurisdiction):
      classification = 'legislature'
      division_id = 'ocd-division/country:ca/province:ab'
      division_name = 'Alberta'
      name = 'Legislative Assembly of Alberta'
      url = 'https://www.assembly.ab.ca'
      parties = [
          {'name': 'Alberta Liberal Party'},
          {'name': 'Alberta New Democratic Party'},
          {'name': 'Alberta Party'},
          {'name': 'Freedom Conservative Party'},
          {'name': 'Independent Conservative'},
          {'name': 'Progressive Conservative Association of Alberta'},
          {'name': 'United Conservative Party'},
          {'name': 'Wildrose Alliance Party'},
          {'name': 'Independent'},
      ]
  
new_contents: from utils import CanadianJurisdiction
  
  
  class Alberta(CanadianJurisdiction):
      classification = 'legislature'
      division_id = 'ocd-division/country:ca/province:ab'
      division_name = 'Alberta'
      name = 'Legislative Assembly of Alberta'
      url = 'https://www.assembly.ab.ca'
      parties = [
          {'name': 'Alberta Liberal Party'},
          {'name': 'Alberta New Democratic Party'},
          {'name': 'Alberta Party'},
          {'name': 'Freedom Conservative Party'},
          {'name': 'Independent Conservative'},
          {'name': 'Progressive Conservative Association of Alberta'},
          {'name': 'United Conservative Party'},
          {'name': 'Wildrose Alliance Party'},
          {'name': 'Independent'},
      ]
      skip_null_valid_from = True
      valid_from = '2019-05-31'
  
subject: Add valid_from