chronos/src/main/java/com/redmadrobot/chronos/RunningOperationStorage.java
private synchronized boolean cancel(final int id, final boolean mayInterrupt,
            final boolean removeOperation) {
        final RunningOperation runningOperation = mRunningOperations.get(id);
        if (runningOperation != null) {
            if (removeOperation) {
                mRunningOperations.remove(id);
            }
            mCancelledOperations.add(id);
            return runningOperation.cancel(mayInterrupt);
        } else {
            return false;
        }
    }
private synchronized boolean cancel(final int id, final boolean mayInterrupt,
            final boolean removeOperation) {
        final RunningOperation runningOperation = mRunningOperations.get(id);
        if (runningOperation != null) {
            if (removeOperation) {
                mRunningOperations.remove(id);
            }
            mCancelledOperations.add(id);
            return runningOperation.cancel(mayInterrupt);
        } else {
            return false;
        }
    }
Cancels running operation.

@param id              the unique id of operations' launch
@param mayInterrupt    {@code true} if thread executing operation task should be interrupted;
otherwise, in-progress tasks are allowed to complete
@param removeOperation {@code true} if the operation should be marked as removed
@return {@code false} if the task could not be cancelled, typically because it has already
completed normally; {@code true} otherwise