def METHOD_NAME(resource_mgr_client: resource_manager.Client,
                    organization_id: int) -> List[str]:
    """Generates list of project_ids within a GCP org.
    Args:
        resource_mgr_client: resource_manager.Client
        organization_id: Integer representing GCP org ID
    Returns:
        List of strings holding all project IDs.
    """
    project_filter = {
        'parent.id': organization_id,
        'parent.type': 'organization'
    }
    return [p.project_id for p in
            resource_mgr_client.list_projects(project_filter)]