code: func (m *txSortedMap) Remove(nonce uint64) bool {
  	// Short circuit if no transaction is present
  	_, ok := m.items[nonce]
  	if !ok {
  		return false
  	}
  	// Otherwise delete the transaction and fix the heap index
  	for i := 0; i < m.index.Len(); i++ {
  		if (*m.index)[i] == nonce {
  			heap.Remove(m.index, i)
  			break
  		}
  	}
  	delete(m.items, nonce)
  	m.cache = nil
  
  	return true
  }
docs: // Remove deletes a transaction from the maintained map, returning whether the
  // transaction was found.