def preload_module(self, name):
        """Preload a module's file data into the index itself.

        This is a little trick to speed up loading of commonly-used modules.
        Rather than having the module's file data as a separate file on disk,
        we store it as a string directly in the index file, and avoid doing
        a separate network access to load it at VM startup time.
        """
        for depname in self._find_transitive_dependencies(name):
            if depname in self.preload:
                continue
            moddata = self.modules[depname]
            if "file" in moddata:
                filepath = os.path.join(self.bundle_dir, moddata["file"])
                with open(filepath, "rb") as f:
                    self.preload[depname] = f.read().decode("utf8")
Preload a module's file data into the index itself.

        This is a little trick to speed up loading of commonly-used modules.
        Rather than having the module's file data as a separate file on disk,
        we store it as a string directly in the index file, and avoid doing
        a separate network access to load it at VM startup time.
        
tools/module_bundler.py