docs: private static Set<CallSite> findObviouslyLockedCallSites(ClassContext classContext, SelfCalls selfCalls)
              throws CFGBuilderException, DataflowAnalysisException {
          ConstantPoolGen cpg = classContext.getConstantPoolGen();
  
          // Find all obviously locked call sites
          Set<CallSite> obviouslyLockedSites = new HashSet<>();
          for (Iterator<CallSite> i = selfCalls.callSiteIterator(); i.hasNext();) {
              CallSite callSite = i.next();
              Method method = callSite.getMethod();
              Location location = callSite.getLocation();
              InstructionHandle handle = location.getHandle();
  
              // Only instance method calls qualify as candidates for
              // "obviously locked"
              Instruction ins = handle.getInstruction();
              if (ins.getOpcode() == Const.INVOKESTATIC) {
                  continue;
              }
  
              // Get lock set for site
              LockChecker lockChecker = classContext.getLockChecker(method);
              LockSet lockSet = lockChecker.getFactAtLocation(location);
  
              // Get value number frame for site
              ValueNumberDataflow vnaDataflow = classContext.getValueNumberDataflow(method);
              ValueNumberFrame frame = vnaDataflow.getFactAtLocation(location);
  
              // NOTE: if the CFG on which the value number analysis was performed
              // was pruned, there may be unreachable instructions. Therefore,
              // we can't assume the frame is valid.
              if (!frame.isValid()) {
                  continue;
              }
  
              // Find the ValueNumber of the receiver object
              int numConsumed = ins.consumeStack(cpg);
              MethodGen methodGen = classContext.getMethodGen(method);
              assert methodGen != null;
              if (numConsumed == Const.UNPREDICTABLE) {
                  throw new DataflowAnalysisException("Unpredictable stack consumption", methodGen, handle);
              }
              // if (DEBUG) System.out.println("Getting receiver for frame: " +
              // frame);
              ValueNumber instance = frame.getStackValue(numConsumed - 1);
  
              // Is the instance locked?
              int lockCount = lockSet.getLockCount(instance.getNumber());
              if (lockCount > 0) {
                  // This is a locked call site
                  obviouslyLockedSites.add(callSite);
              }
          }
  
          return obviouslyLockedSites;
      }