 ![ [*Left panel*]{}: $E_{\rm peak}$ distributions for GRBs that are better fitted by the CPL model. [*Right panel*]{}: Photon index $\alpha_{\rm CPL}$ distributions for GRBs that are better fitted by the CPL model. Distributions using the upper and lower bounds of the $E_{\rm peak}$/$\alpha_{\rm CPL}$ uncertainty range are also plotted for comparison. []{data-label="fig:Epeak"}](