我的项目有以下依赖树：
+---+--- com.android.support:appcompat-v7:21.0.3
| \--- com.android.support:support-v4:21.0.3
| \--- com.android.support:support-annotations:21.0.3
\--- io.pivotal:arca:1.0-beta.3
+--- io.pivotal:arca-core:1.0-beta.3
| +--- io.pivotal:arca-service:1.0-beta.3
| | +--- io.pivotal:arca-threading:1.0-beta.3
| | \--- io.pivotal:arca-utils:1.0-beta.3
| +--- io.pivotal:arca-threading:1.0-beta.3
| +--- io.pivotal:arca-provider:1.0-beta.3
| | \--- io.pivotal:arca-utils:1.0-beta.3
| +--- io.pivotal:arca-utils:1.0-beta.3
| \--- io.pivotal:arca-broadcaster:1.0-beta.3
\--- io.pivotal:arca-app:1.0-beta.3
+--- io.pivotal:arca-monitor:1.0-beta.3
| \--- io.pivotal:arca-dispatcher:1.0-beta.3
| \--- io.pivotal:arca-broadcaster:1.0-beta.3
+--- io.pivotal:arca-adapters:1.0-beta.3
+--- io.pivotal:arca-fragments:1.0-beta.3
| +--- io.pivotal:arca-monitor:1.0-beta.3 (*)
| \--- io.pivotal:arca-dispatcher:1.0-beta.3 (*)
\--- io.pivotal:arca-dispatcher:1.0-beta.3 (*)
请注意标有*的树叶，因为它们是重复的;我该如何解决这些重复问题？