docs: public File getSolrSchemaFile() {
  
          final String dir = getHome() + DEFAULT_CONFIGSET_FOLDER + CONF_FOLDER;
          //SOLR7 Schema took a new name, also removed the file extension.
          File file = new File(dir, "managed-schema");
          if (file.exists()) {
              return file;
          }
  
          //If use the old Schema.xml, it will automatically "upgrade" to a new filename.
          file = new File(dir, IndexSchema.DEFAULT_SCHEMA_FILE);
          return file;
      }