inventorycollection.json

{
    _id: 1,
    item: "abc",
    stock: [
        { size: "S", color: "red", quantity: 25
        },
        { size: "S", color: "blue", quantity: 10
        },
        { size: "M", color: "blue", quantity: 50
        }
    ]
}
  {
    _id: 2,
    item: "def",
    stock: [
        { size: "S", color: "blue", quantity: 20
        },
        { size: "M", color: "blue", quantity: 5
        },
        { size: "M", color: "black", quantity: 10
        },
        { size: "L", color: "red", quantity: 2
        }
    ]
}
  {
    _id: 3,
    item: "ijk",
    stock: [
        { size: "M", color: "blue", quantity: 15
        },
        { size: "L", color: "blue", quantity: 100
        },
        { size: "L", color: "red", quantity: 25
        }
    ]
}