A series circuit consists of an ideal battery of electromotive force (emf) \(\varepsilon = 12\text{ V}\), a resistor of resistance \(R = 3.0\text{ k}\Omega\), an open switch, and an uncharged capacitor of unknown capacitance \(C\). At time \(t = 0\text{ s}\), the switch is closed, and a current sensor records the current \(I\) in the circuit as a function of time \(t\), as shown in the graph. Based on the graph, what is the capacitance \(C\) of the capacitor?