public VmTraceData build() { for (int i = 0; i < mStackReconstructors.size(); i++) { int threadId = mStackReconstructors.keyAt(i); CallStackReconstructor reconstructor = mStackReconstructors.valueAt(i); mTopLevelCalls.put(threadId, reconstructor.getTopLevel()); } return new VmTraceData(this); }