Let \(f\) be a non-constant holomorphic function on \(\mathbb{C}\) and \(Z=X+i Y\) a complex Brownian motion. Prove that there exists another complex Brownian motion \(B\) such that \(f\left(Z_{t}\right)=f\left(Z_{0}\right)+B\left(\int_{0}^{t}\left|f^{\prime}\left(Z_{s}\right)\right|^{2} d\langle Xangle_{s}\right)\). As an example, \(\exp \left(Z_{t}\right)=1+B_{\int_{0}^{t} d s \exp \left(2 X_{s}\right)}\).