Null too, why not

src/package-url.d.ts

@@ -38,7 +38,7 @@ declare module "packageurl-js" {
  /**
  * some name prefix such as a Maven groupid, a Docker image owner, a GitHub user or organization. Optional and type-specific.
  */
- namespace: string | undefined;
+ namespace: string | undefined | null;
 
  /**
  * the name of the package. Required.
@@ -48,22 +48,26 @@ declare module "packageurl-js" {
  /**
  * the version of the package. Optional.
  */
- version: string | undefined;
+ version: string | undefined | null;
 
  /**
  * extra qualifying data for a package such as an OS, architecture, a distro, etc. Optional and type-specific.
  */
  qualifiers: {
  [key: string]: string;
- } | undefined;
+ } | undefined | null;
 
  /**
  * extra subpath within a package, relative to the package root. Optional.
  */
- subpath: string | undefined;
-
- constructor(type: string, namespace: string | undefined, name: string, version: string | undefined,
- qualifiers: { [key: string]: string; } | undefined, subpath: string | undefined);
+ subpath: string | undefined | null;
+
+ constructor(type: string, 
+ namespace: string | undefined | null, 
+ name: string, 
+ version: string | undefined | null,
+ qualifiers: { [key: string]: string; } | undefined | null, 
+ subpath: string | undefined | null);
 
  /**
  * Converts the PackageURL to a string