ntype"><a href="dart-async/ZoneBinaryCallback.html">ZoneBinaryCallback</a><span class="signature">&lt;<wbr><span class="type-parameter">R</span>, <span class="type-parameter">T1</span>, <span class="type-parameter">T2</span>&gt;</span></span>
                <span class="name ">RegisterBinaryCallbackHandler</span>
&lt;<wbr><span class="type-parameter">R</span>, <span class="type-parameter">T1</span>, <span class="type-parameter">T2</span>&gt;(<wbr><span class="parameter" id="RegisterBinaryCallbackHandler-pa