Testing the Ge detectors for the \textsc{Majorana} \textsc{Demonstrator}

High purity germanium (HPGe) crystals will be used for the \textsc{Majorana} \textsc{Demonstrator}, where they serve as both the source and the detector for neutrinoless double beta decays. It is crucial for the experiment to understand the performances of the HPGe crystals. A variety of crystal properties are being investigated, including both basic properties such as energy resolution, efficiency, uniformity, capacitance, leakage current and crystal axis orientation, as well as more sophisticated properties, \textit{e.g.} pulse shapes and dead layer and transition layer distribution. In this talk, we will present our measurements that characterize the HPGe crystals. We will also discuss the experiment's simulation package for the detector characterization setup, where additional information is learned from data-simulation comparisons.