How to set the height for a specific row in a “longtable”?

I have a "longtable" and I need a couple of rows to be "taller" than the others. Is it possible to specify a fixed height for a specific row?

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\rule{0pt}{whatever_you_want}


is the better choice and if you need a depth:

\rule[shift]{0pt}{whatever_you_want}

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Oh well, I've created an empty box within the cell, like this:

\vbox to 1cm {\vfil
\hbox to 3cm{}%
\vfil
}


Probably not the best method to do this, but it works.

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