diff --git a/ultrasonic/src/main/kotlin/org/moire/ultrasonic/playback/UltrasonicCache.kt b/ultrasonic/src/main/kotlin/org/moire/ultrasonic/playback/UltrasonicCache.kt
deleted file mode 100644
index f3b59499..00000000
--- a/ultrasonic/src/main/kotlin/org/moire/ultrasonic/playback/UltrasonicCache.kt
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * UltrasonicCache.kt
- * Copyright (C) 2009-2022 Ultrasonic developers
- *
- * Distributed under terms of the GNU GPLv3 license.
- */
-
-package org.moire.ultrasonic.playback
-
-import androidx.media3.common.util.UnstableApi
-import androidx.media3.datasource.cache.Cache
-import androidx.media3.datasource.cache.CacheSpan
-import androidx.media3.datasource.cache.ContentMetadata
-import androidx.media3.datasource.cache.ContentMetadataMutations
-import java.io.File
-import java.util.NavigableSet
-
-@UnstableApi
-
-class UltrasonicCache : Cache {
-    override fun getUid(): Long {
-        TODO("Not yet implemented")
-    }
-
-    override fun release() {
-        // R/O Cache Implementation
-    }
-
-    override fun addListener(key: String, listener: Cache.Listener): NavigableSet<CacheSpan> {
-        // Not (yet?) implemented
-        return emptySet<CacheSpan>() as NavigableSet<CacheSpan>
-    }
-
-    override fun removeListener(key: String, listener: Cache.Listener) {
-        // Not (yet?) implemented
-    }
-
-    override fun getCachedSpans(key: String): NavigableSet<CacheSpan> {
-        TODO("Not yet implemented")
-    }
-
-    override fun getKeys(): MutableSet<String> {
-        TODO("Not yet implemented")
-    }
-
-    override fun getCacheSpace(): Long {
-        TODO("Not yet implemented")
-    }
-
-    override fun startReadWrite(key: String, position: Long, length: Long): CacheSpan {
-        TODO("Not yet implemented")
-    }
-
-    override fun startReadWriteNonBlocking(key: String, position: Long, length: Long): CacheSpan? {
-        TODO("Not yet implemented")
-    }
-
-    override fun startFile(key: String, position: Long, length: Long): File {
-        // R/O Cache Implementation
-        return File("NONE")
-    }
-
-    override fun commitFile(file: File, length: Long) {
-        // R/O Cache Implementation
-    }
-
-    override fun releaseHoleSpan(holeSpan: CacheSpan) {
-        TODO("Not yet implemented")
-    }
-
-    override fun removeResource(key: String) {
-        // R/O Cache Implementation
-    }
-
-    override fun removeSpan(span: CacheSpan) {
-        // R/O Cache Implementation
-    }
-
-    override fun isCached(key: String, position: Long, length: Long): Boolean {
-        TODO("Not yet implemented")
-    }
-
-    override fun getCachedLength(key: String, position: Long, length: Long): Long {
-        TODO("Not yet implemented")
-    }
-
-    override fun getCachedBytes(key: String, position: Long, length: Long): Long {
-        TODO("Not yet implemented")
-    }
-
-    override fun applyContentMetadataMutations(key: String, mutations: ContentMetadataMutations) {
-        TODO("Not yet implemented")
-    }
-
-    override fun getContentMetadata(key: String): ContentMetadata {
-        TODO("Not yet implemented")
-    }
-
-}