docs: func s3ControlCustomizations(a *API) {
  	for opName, op := range a.Operations {
  		// Add moving AccountId into the hostname instead of header.
  		if ref, ok := op.InputRef.Shape.MemberRefs["AccountId"]; ok {
  			if op.Endpoint != nil {
  				fmt.Fprintf(os.Stderr, "S3 Control, %s, model already defining endpoint trait, remove this customization.\n", opName)
  			}
  
  			op.Endpoint = &EndpointTrait{HostPrefix: "{AccountId}."}
  			ref.HostLabel = true
  		}
  	}
  }