Reduce chance of conflict with other agents (#555)
diff --git a/org.jacoco.doc/docroot/doc/implementation.html b/org.jacoco.doc/docroot/doc/implementation.html
index bea6f73..b1eda7f 100644
--- a/org.jacoco.doc/docroot/doc/implementation.html
+++ b/org.jacoco.doc/docroot/doc/implementation.html
@@ -215,7 +215,9 @@
<p>
The current JaCoCo Java agent implementation uses the
<code>ModifiedSystemClassRuntime</code> adding a field to the class
- <code>java.util.UUID</code>.
+ <code>java.lang.UnknownError</code>. Versions 0.5.0 - 0.7.9 were adding field
+ to the class <code>java.util.UUID</code>, having bigger chance of conflict
+ with other agents.
</p>