code: func (e *baseError) GetStack() string {
  	stackFrames := e.StackFrames()
  	buf := bytes.NewBuffer(make([]byte, 0, 256))
  	for _, frame := range stackFrames {
  		_, _ = buf.WriteString(frame.FuncName)
  		_, _ = buf.WriteString("\n")
  		fmt.Fprintf(buf, "\t%s:%d +0x%x\n",
  			frame.File, frame.LineNumber, frame.PC)
  	}
  	return buf.String()
  }
docs: // Implements DropboxError interface.