code: def default_bucket(self):
          
          if self._default_bucket:
              return self._default_bucket
  
          account = self.boto_session.client('sts').get_caller_identity()['Account']
          region = self.boto_session.region_name
          default_bucket = 'sagemaker-{}-{}'.format(region, account)
  
          s3 = self.boto_session.resource('s3')
          try:
              # 'us-east-1' cannot be specified because it is the default region:
              # https://github.com/boto/boto3/issues/125
              if region == 'us-east-1':
                  s3.create_bucket(Bucket=default_bucket)
              else:
                  s3.create_bucket(Bucket=default_bucket, CreateBucketConfiguration={'LocationConstraint': region})
  
              LOGGER.info('Created S3 bucket: {}'.format(default_bucket))
          except ClientError as e:
              error_code = e.response['Error']['Code']
              message = e.response['Error']['Message']
  
              if error_code == 'BucketAlreadyOwnedByYou':
                  pass
              elif error_code == 'OperationAborted' and 'conflicting conditional operation' in message:
                  # If this bucket is already being concurrently created, we don't need to create it again.
                  pass
              elif error_code == 'TooManyBuckets':
                  # Succeed if the default bucket exists
                  s3.meta.client.head_bucket(Bucket=default_bucket)
              else:
                  raise
  
          self._default_bucket = default_bucket
  
          return self._default_bucket
docs: Return the name of the default bucket to use in relevant Amazon SageMaker interactions.
  
          Returns:
              str: The name of the default bucket, which is of the form: ``sagemaker-{region}-{AWS account ID}``.