code: private void sawInitOpcode(int seen) {
          boolean isSyncCollection = false;
          try {
              stack.mergeJumps(this);
              isSyncCollection = isSyncCollectionCreation(seen);
              if (seen == Const.PUTFIELD) {
                  processCollectionStore();
              }
          } finally {
              stack.sawOpcode(this, seen);
              if (isSyncCollection && (stack.getStackDepth() > 0)) {
                  OpcodeStack.Item item = stack.getStackItem(0);
                  item.setUserValue(Boolean.TRUE);
              }
          }
      }
docs: handle {@code <init>} blocks by looking for putfield calls referencing synchronized collections
  
  @param seen
  the opcode of the currently parsed instruction