height of Empty row in the dropdown

Hi All,

I am trying to add a Blank text row to a dropdown.I was able to set a blank record in the store and showing it at the first index.

The problem is if i am giving blank value the height of the row is tiny(almost half of the other rows) than the other value's row.

Can anyone please help me in the issue how the height of the blank record can be equal to the height of other rows (Other Values in the drop down)?

Thanks in advance,

Ankit