return nil, &NetworkError{Err: c.LastError()}
	}

	// client is still connected, attempt the request.

	// Shallow copy. We don't modify the *UserInfo, if set.
	// All other fields are copied.
	u := *c.url
	u.Path = path.Join(u.Path, rpcMethod)
	u.RawQuery = values.Encode()

	req, err := c.newRequest(ctx, httpMethod, u, body)
	if err != nil {
		return nil, &NetworkError{Err: err}

   * this is subject to change. Also, {@code junit4.TearDownTestCase} will.
   *
   * @throws Exception for any reason. {@code TearDownTestCase} ensures that any exception thrown
   *     will not interfere with other TearDown operations.
   */
  void tearDown() throws Exception;

import org.apache.maven.api.cli.extensions.CoreExtension;

import static java.util.Objects.requireNonNull;

/**
 * Represents the list of core extensions configured at one source. The list is validated (are GA unique), but no
 * other logic than that is applied.
 *
 * @since 4.0.0
 * @param source The source file of core extensions, is never {@code null}.

And these models are all sharing a lot of the data and duplicating attribute names and types.

We could do better.

We can declare a `UserBase` model that serves as a base for our other models. And then we can make subclasses of that model that inherit its attributes (type declarations, validation, etc).

    /** The time taken to execute the search query in milliseconds. */
    protected final long queryTime;

    /** Flag indicating whether the search results are partial due to timeout or other constraints. */
    protected final boolean partialResults;

    /** The facet response containing aggregated facet information for the search results. */
    protected final FacetResponse facetResponse;

    /**

 * then Lock B, while another thread acquires Lock B, and then Lock A:
 *
 * <pre>
 * Thread1: acquire(LockA) --X acquire(LockB)
 * Thread2: acquire(LockB) --X acquire(LockA)
 * </pre>
 *
 * <p>Neither thread will progress because each is waiting for the other. In more complex
 * applications, cycles can arise from interactions among more than 2 locks:
 *

   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity
   * as an element is indicated by the presence or absence of {@link #ALLOWS_NULL_VALUES}). From the
   * documentation for {@link Collection}:
   *
   * <blockquote>
   *

    Optional<Boolean> infer();

    /**
     * Should fix Maven 4 compatibility issues in POMs.
     * This includes fixing unsupported combine attributes, duplicate dependencies,
     * unsupported expressions, and other Maven 4 validation issues.
     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    @Nonnull
    Optional<Boolean> model();

    /**

 *
 * 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 specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

    protected long currentEndRecordNumber;

    /** List of page numbers for pagination navigation. */
    protected List<String> pageNumberList;

    /** Flag indicating whether the results are partial due to timeout or other issues. */
    protected boolean partialResults;

    /** The actual search query executed against the search engine. */
    protected String searchQuery;

    /** Time taken to execute the search query in milliseconds. */