code: def to_project(project):
          
          from sevenbridges.models.project import Project
          if not project:
              raise SbgError('Project is required!')
          elif isinstance(project, Project):
              return project.id
          elif isinstance(project, six.string_types):
              return project
          else:
              raise SbgError('Invalid project parameter!')
docs: Serializes project to id string
          :param project: object to serialize
          :return: string id