class="pre">=</span></span><span class="default_value"><span class="pre">'BBH'</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">source_priors</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">source_priors_params</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, 