code: function computeSpecifierMap(specifiers) {
    const specifierCount = specifiers.length;
    const specifierMap = Object.create(null);
  
    for (let i = 0; i < specifierCount; ++i) {
      const s = specifiers[i];
  
      const local =
        s.type === "ExportDefaultSpecifier" ? "default" :
        s.type === "ExportNamespaceSpecifier" ? "*" :
        s.local.name;
  
      const __ported = // The IMported or EXported name.
        s.type === "ImportSpecifier" ? s.imported.name :
        s.type === "ImportDefaultSpecifier" ? "default" :
        s.type === "ImportNamespaceSpecifier" ? "*" :
        (s.type === "ExportSpecifier" ||
         s.type === "ExportDefaultSpecifier" ||
         s.type === "ExportNamespaceSpecifier") ? s.exported.name :
        null;
  
      if (typeof local === "string" && typeof __ported === "string") {
        addToSpecifierMap(specifierMap, __ported, local);
      }
    }
  
    return specifierMap;
  }
docs: Returns a map from {im,ex}ported identifiers to lists of local variable names bound to those identifiers.