code: func (client *Client) GetOrganizationDefaultIsolationSegment(orgGUID string) (Relationship, Warnings, error) {
  	request, err := client.newHTTPRequest(requestOptions{
  		RequestName: internal.GetOrganizationRelationshipDefaultIsolationSegmentRequest,
  		URIParams:   internal.Params{"organization_guid": orgGUID},
  	})
  	if err != nil {
  		return Relationship{}, nil, err
  	}
  
  	var relationship Relationship
  	response := cloudcontroller.Response{
  		DecodeJSONResponseInto: &relationship,
  	}
  
  	err = client.connection.Make(request, &response)
  	return relationship, response.Warnings, err
  }
docs: // GetOrganizationDefaultIsolationSegment returns the relationship between an
  // organization and it's default isolation segment.