code: func (tx *transaction) deleteKey(key []byte, notifyIterators bool) {
  	// Remove the key from the list of pendings keys to be written on
  	// transaction commit if needed.
  	tx.pendingKeys.Delete(key)
  
  	// Add the key to the list to be deleted on transaction	commit.
  	tx.pendingRemove.Put(key, nil)
  
  	// Notify the active iterators about the change if the flag is set.
  	if notifyIterators {
  		tx.notifyActiveIters()
  	}
  }
docs: // deleteKey adds the provided key to the list of keys to be deleted from the
  // database when the transaction is committed.  The notify iterators flag is
  // useful to delay notifying iterators about the changes during bulk deletes.
  //
  // NOTE: This function must only be called on a writable transaction.  Since it
  // is an internal helper function, it does not check.