public <A, X extends GenericRequestBuilder<A, ?, ?, ?>> X apply(X builder) {
            if (options != null) {
                options.apply(builder);
            }
            return builder;
        }
Sets the resource class that will be loaded.

@param resourceClass The class of the resource that will be loaded.
@param <Z> The type of the resource that will be loaded.
@return This request builder.
core/src/main/java/com/bumptech/glide/RequestManager.java