code: private String getEs6ModuleNameFromImportNode(NodeTraversal t, Node n) {
      String importName = n.getLastChild().getString();
      boolean isNamespaceImport = importName.startsWith("goog:");
      if (isNamespaceImport) {
        // Allow importing Closure namespace objects (e.g. from goog.provide or goog.module) as
        //   import ... from 'goog:my.ns.Object'.
        // These are rewritten to plain namespace object accesses.
        return importName.substring("goog:".length());
      } else {
        ModuleLoader.ModulePath modulePath =
            t.getInput()
                .getPath()
                .resolveJsModule(importName, n.getSourceFileName(), n.getLineno(), n.getCharno());
        if (modulePath == null) {
          // The module loader issues an error
          // Fall back to assuming the module is a file path
          modulePath = t.getInput().getPath().resolveModuleAsPath(importName);
        }
        return modulePath.toModuleName();
      }
    }
docs: Get the module name from an import node (import or export statement).