final Meeting meetingForUpdate = this.meetingRepositoryWrapper.findOneWithNotFoundDetection(command.entityId());
final Collection<ClientAttendance> clientsAttendance = getClientsAttendance(meetingForUpdate, command);
final Map<String, Object> changes = meetingForUpdate.updateAttendance(clientsAttendance);
this.meetingRepositoryWrapper.saveAndFlush(meetingForUpdate);
final Long groupId = meetingForUpdate.isGroupEntity() ? meetingForUpdate.entityId() : null;
return new CommandProcessingResultBuilder() //
.withEntityId(meetingForUpdate.getId()) //
.withGroupId(groupId) //
.with(changes) //
.build();