code: def __parse_organizations(self, stream):
          
          if not stream:
              return
  
          yaml_file = self.__load_yml(stream)
  
          try:
              for element in yaml_file:
                  name = self.__encode(element['organization'])
  
                  if not name:
                      error = "Empty organization name"
                      msg = self.GRIMOIRELAB_INVALID_FORMAT % {'error': error}
                      raise InvalidFormatError(cause=msg)
  
                  o = Organization(name=name)
  
                  if 'domains' in element:
                      if not isinstance(element['domains'], list):
                          error = "List of elements expected for organization %s" % name
                          msg = self.GRIMOIRELAB_INVALID_FORMAT % {'error': error}
                          raise InvalidFormatError(cause=msg)
                      for dom in element['domains']:
                          if dom:
                              d = Domain(domain=dom, is_top_domain=False)
                              o.domains.append(d)
                          else:
                              error = "Empty domain name for organization %s" % name
                              msg = self.GRIMOIRELAB_INVALID_FORMAT % {'error': error}
                              raise InvalidFormatError(cause=msg)
  
                  self._organizations[name] = o
          except KeyError as e:
              error = "Attribute %s not found" % e.args
              msg = self.GRIMOIRELAB_INVALID_FORMAT % {'error': error}
              raise InvalidFormatError(cause=msg)
          except TypeError as e:
              error = "%s" % e.args
              msg = self.GRIMOIRELAB_INVALID_FORMAT % {'error': error}
              raise InvalidFormatError(cause=msg)
docs: Parse GrimoireLab organizations.
  
          The GrimoireLab organizations format is a YAML element stored
          under the "organizations" key. The next example shows the
          structure of the document:
  
          - organizations:
              Bitergia:
                  - bitergia.com
                  - support.bitergia.com
                  - biterg.io
              LibreSoft:
                  - libresoft.es
  
          :param json: YAML object to parse
  
          :raises InvalidFormatError: raised when the format of the YAML is
              not valid.