What does the Unknown -tag mean when you open (Android) heap dump with MAT, go to histogram, the then select e.g. "merge shortest paths..." for your class of interest?
Like here:
class android.view.inputmethod.InputMethodManager @ 0x40b083f8 Unknown
There can be also other tags like Thread or System class with the Unknown.
I ask this as someone claimed that the Unknowns are subject to GC and could thus be ignored in memory leak analysis. I failed to find a reliable source for this. Can someone verify this?