code: func (v *VaultProvider) getCA(path string) (string, error) {
  	req := v.client.NewRequest("GET", "/v1/"+path+"/ca/pem")
  	resp, err := v.client.RawRequest(req)
  	if resp != nil {
  		defer resp.Body.Close()
  	}
  	if resp != nil && resp.StatusCode == http.StatusNotFound {
  		return "", ErrBackendNotMounted
  	}
  	if err != nil {
  		return "", err
  	}
  
  	bytes, err := ioutil.ReadAll(resp.Body)
  	if err != nil {
  		return "", err
  	}
  
  	root := string(bytes)
  	if root == "" {
  		return "", ErrBackendNotInitialized
  	}
  
  	return root, nil
  }
docs: // getCA returns the raw CA cert for the given endpoint if there is one.
  // We have to use the raw NewRequest call here instead of Logical().Read
  // because the endpoint only returns the raw PEM contents of the CA cert
  // and not the typical format of the secrets endpoints.