ass="parameters">(<a href="CustomStreamSeekCallback.Function.html" title="interface in app.photofox.vipsffm.jextract">CustomStreamSeekCallback.Function</a>&nbsp;fi,
 <a href="https://docs.oracle.com/en/java/javase/23/docs/api/java.base/java/lang/foreign/Arena.html" title="class or interface in java.lang.foreign" class="external-link">Arena</a>&nbsp;arena)</span></div>
<div class="block">Allocates a new upcall stub, whose implementation is defined by <code>fi</code>.
 The lifetime of the returned segment is 