@Override public boolean remove(@Nullable Object o) { if (o instanceof Cell) { Cell<?, ?, ?> cell = (Cell<?, ?, ?>) o; Map<C, V> row = Maps.safeGet(rowMap(), cell.getRowKey()); return row != null && Collections2.safeRemove( row.entrySet(), Maps.immutableEntry(cell.getColumnKey(), cell.getValue())); } return false; }