Hello I have kind of complicated iteration to be done over an array of objects. I have array like this:

```
[ 
  { name: 'Jacob', lastName: 'Smith', dob: '1995-11-29' },
  { name: 'Jacob', lastName: 'Smith', dob: '1991-08-21' },
  { name: 'Ann', lastName: 'Smith', dob: '1995-11-29' },
  { name: 'Ann', lastName: 'Nansen', dob: '1983-01-01' },
  { name: 'Jacob', lastName: 'Smith', dob: '1985-06-15' },
  { name: 'Jacob', lastName: 'Smith', dob: '1995-11-29' },
  { name: 'Ann', lastName: 'Smith', dob: '2010-11-29' },
]

```

I would like to add count property to each object that counts objects with same name and surname... So it should be now:

```
[ 
  { name: 'Jacob', lastName: 'Smith', count: 4 },
  { name: 'Ann', lastName: 'Smith', count: 2 },
  { name: 'Ann', lastName: 'Nansen', count: 1' },
]

```