code: func (client *Client) CreateIsolationSegment(isolationSegment IsolationSegment) (IsolationSegment, Warnings, error) {
  	body, err := json.Marshal(isolationSegment)
  	if err != nil {
  		return IsolationSegment{}, nil, err
  	}
  
  	request, err := client.newHTTPRequest(requestOptions{
  		RequestName: internal.PostIsolationSegmentsRequest,
  		Body:        bytes.NewReader(body),
  	})
  	if err != nil {
  		return IsolationSegment{}, nil, err
  	}
  
  	var responseIsolationSegment IsolationSegment
  	response := cloudcontroller.Response{
  		DecodeJSONResponseInto: &responseIsolationSegment,
  	}
  
  	err = client.connection.Make(request, &response)
  	return responseIsolationSegment, response.Warnings, err
  }
docs: // CreateIsolationSegment will create an Isolation Segment on the Cloud
  // Controller. Note: This will not validate that the placement tag exists in
  // the diego cluster.