apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/ConfigsImportService.java/NamespaceImportData/toString
class NamespaceImportData:    @Override
    public String toString() {
      return "NamespaceImportData{" +
             "env=" + env +
             ", fileName='" + fileName + '\'' +
             ", content='" + content + '\'' +
             ", ignoreConflictNamespace=" + ignoreConflictNamespace +
             '}';
    }