Consider a signal \(x\left( n \right) = \left\{ { - 1,\;2,\;\begin{array}{*{20}{c}} 4\\ \uparrow \end{array},\;2,\; - 1,\;3} \right\}\) . What is \(\mathop \smallint \nolimits_{ - \pi }^\pi X\left( \omega \right)d\omega ?\)