code: func (actor Actor) GetEffectiveIsolationSegmentBySpace(spaceGUID string, orgDefaultIsolationSegmentGUID string) (IsolationSegment, Warnings, error) {
  	relationship, warnings, err := actor.CloudControllerClient.GetSpaceIsolationSegment(spaceGUID)
  	allWarnings := append(Warnings{}, warnings...)
  	if err != nil {
  		return IsolationSegment{}, allWarnings, err
  	}
  
  	effectiveGUID := relationship.GUID
  	if effectiveGUID == "" {
  		if orgDefaultIsolationSegmentGUID != "" {
  			effectiveGUID = orgDefaultIsolationSegmentGUID
  		} else {
  			return IsolationSegment{}, allWarnings, actionerror.NoRelationshipError{}
  		}
  	}
  
  	isolationSegment, warnings, err := actor.CloudControllerClient.GetIsolationSegment(effectiveGUID)
  	allWarnings = append(allWarnings, warnings...)
  	if err != nil {
  		return IsolationSegment{}, allWarnings, err
  	}
  
  	return IsolationSegment(isolationSegment), allWarnings, err
  }
docs: // GetEffectiveIsolationSegmentBySpace returns the space's effective isolation
  // segment.
  //
  // If the space has its own isolation segment, that will be returned.
  //
  // If the space does not have one, the organization's default isolation segment
  // (GUID passed in) will be returned.
  //
  // If the space does not have one and the passed in organization default
  // isolation segment GUID is empty, a NoRelationshipError will be returned.