core/src/com/google/inject/internal/BytecodeGen.java
private static ClassLoader canonicalize(ClassLoader classLoader) {
    return classLoader != null ? classLoader : SystemBridgeHolder.SYSTEM_BRIDGE.getParent();
  }
private static ClassLoader canonicalize(ClassLoader classLoader) {
    return classLoader != null ? classLoader : SystemBridgeHolder.SYSTEM_BRIDGE.getParent();
  }
Attempts to canonicalize null references to the system class loader. May return null if for
some reason the system loader is unavailable.