usedTypes.clear();
            }
        }
    }

    @Override
    public Optional<Type> lookup(String id) {
        return Optional.of(require(id));
    }

    @Override
    @Nonnull
    public Type require(String id) {
        nonNull(id, "id");
        return usedTypes.computeIfAbsent(id, i -> {
            Type type = types.get(id);
            if (type == null) {

        return getService(TypeRegistry.class).require(id);
    }

    @Override
    public Language requireLanguage(String id) {
        return getService(LanguageRegistry.class).require(id);
    }

    @Override
    public Packaging requirePackaging(String id) {
        return getService(PackagingRegistry.class).require(id);
    }

    @Override

                        throw new IllegalStateException(e);
                    }
                }
            }
            throw new IllegalArgumentException("The use of session scoped proxies require "
                    + "a org.eclipse.sisu.Typed or javax.enterprise.inject.Typed annotation");
        }
    }

    /**
     * A provider wrapping an existing provider with a cache

     * create a custom {@code Type} for it.
     *
     * @param id the id of the type to retrieve
     * @return the type
     */
    @Nonnull
    @Override
    default Type require(@Nonnull String id) {
        return lookup(id).orElseThrow(() -> new IllegalArgumentException("Unknown extensible enum value '" + id + "'"));
    }

                    problems,
                    Severity.FATAL,
                    Version.V40,
                    "model",
                    null,
                    "the model contains elements that require a model version of " + minVersion,
                    m);
        }

        Parent parent = m.getParent();

        if (parent != null) {
            validateStringNotEmpty(

      <fields>
        <field>
          <name>groupId</name>
          <required>true</required>
          <version>1.0.0+</version>
          <type>String</type>
          <description>The group id of the dependency.</description>
        </field>
        <field>
          <name>artifactId</name>
          <required>true</required>
          <version>1.0.0+</version>
          <type>String</type>

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the