code: private void removeInstalledFeature(String feature, String namespace)
      {
          // Extensions namespaces by feature
  
          if (namespace == null) {
              this.extensionNamespaceByFeature.remove(feature);
          } else {
              Map<String, InstalledFeature> namespaceInstalledExtension = this.extensionNamespaceByFeature.get(feature);
  
              namespaceInstalledExtension.remove(namespace);
          }
      }
docs: Uninstall provided extension.
  
  @param feature the feature to uninstall
  @param namespace the namespace
  @see #uninstallExtension(LocalExtension, String)