code: public static boolean ensureSameSignature(Context context, String targetPackageName) {
          return ensureSameSignature(context, targetPackageName, getSignatureHexCode(context));
      }
docs: Ensure the running application and the target package has the same signature.
  @param context the running application context.
  @param targetPackageName the target package name.
  @return true if the same signature.