I have got an array of arrays like so:

```
[
  [ 48, 28 ], [ 36, 19 ],
  [ 54, 12 ], [ 24, 12 ],
  [ 30, 12 ], [ 42, 12 ],
  [ 40, 10 ], [ 48, 4 ],
  [ 12, 4 ],  [ 18, 3 ],
  [ 20, 2 ],  [ 36, 1 ]
]

```

I would like to filter duplicates based on the first value of each item: `item[0]`. For instance, for the array above I would like to remove `[48, 4]` and `[36, 1]` from it because it already includes `[48, 28]` and `[36, 19]`. Thanks by advance for your help.