public void set(T hardReference) {
    softRef1 = new SoftReference<T>(hardReference);
    softRef2 = new SoftReference<T>(hardReference);
    softRef3 = new SoftReference<T>(hardReference);
  }
To eliminate the possibility of some of our objects causing an OutOfMemoryError when they are not
used, we reference them via SoftReferences. What is a SoftReference? <a
href="http://developer.android.com/reference/java/lang/ref/SoftReference.html"></a> <a
href="http://docs.oracle.com/javase/7/docs/api/java/lang/ref/SoftReference.html"></a> A Soft
Reference is a reference that is cleared when its referent is not strongly reachable and there is
memory pressure. SoftReferences as implemented by Dalvik blindly treat every second SoftReference
as a WeakReference every time a garbage collection happens, - i.e. clear it unless there is
something else referring to it: <a href="https://goo.gl/Pe6aS7">dalvik</a> <a
href="https://goo.gl/BYaUZE">art</a> It will however clear every SoftReference if we don't have
enough memory to satisfy an allocation after a garbage collection.

<p>This means that as long as one of the soft references stays alive, they all stay alive. If we
have two SoftReferences next to each other on the heap, both pointing to the same object, then we
are guaranteed that neither will be cleared until we otherwise would have thrown an
OutOfMemoryError. Since we can't strictly guarantee the location of objects on the heap, we use 3
just to be on the safe side. TLDR: It's a reference that's cleared if and only if we otherwise
would have encountered an OOM.
fbcore/src/main/java/com/facebook/common/references/OOMSoftReference.java