code: func (client *Client) EntitleIsolationSegmentToOrganizations(isolationSegmentGUID string, organizationGUIDs []string) (RelationshipList, Warnings, error) {
  	body, err := json.Marshal(RelationshipList{GUIDs: organizationGUIDs})
  	if err != nil {
  		return RelationshipList{}, nil, err
  	}
  
  	request, err := client.newHTTPRequest(requestOptions{
  		RequestName: internal.PostIsolationSegmentRelationshipOrganizationsRequest,
  		URIParams:   internal.Params{"isolation_segment_guid": isolationSegmentGUID},
  		Body:        bytes.NewReader(body),
  	})
  	if err != nil {
  		return RelationshipList{}, nil, err
  	}
  
  	var relationships RelationshipList
  	response := cloudcontroller.Response{
  		DecodeJSONResponseInto: &relationships,
  	}
  
  	err = client.connection.Make(request, &response)
  	return relationships, response.Warnings, err
  }
docs: // EntitleIsolationSegmentToOrganizations will create a link between the
  // isolation segment and the list of organizations provided.