Banning duplicate classes

gistfile1.xml

                    <plugin>
                        <artifactId>maven-enforcer-plugin</artifactId>
                        <version>1.0.1</version>
                        <inherited>true</inherited>
                        <executions>
                            <execution>
                                <id>enforce-no-duplicate-classes</id>
                                <goals>
                                    <goal>enforce</goal>
                                </goals>
                                <configuration>
                                    <rules>
                                        <banDuplicateClasses>
                                            <findAllDuplicates>true</findAllDuplicates>
                                        </banDuplicateClasses>
                                    </rules>
                                </configuration>
                            </execution>
                        </executions>
                        <dependencies>
                            <dependency>
                                <groupId>org.codehaus.mojo</groupId>
                                <artifactId>extra-enforcer-rules</artifactId>
                                <version>1.0-alpha-1</version>
                            </dependency>
                        </dependencies>
                    </plugin>