refactor(internal): polish ClientOptions

Author: stainless-bot

openai-java-core/src/main/kotlin/com/openai/core/Utils.kt

@@ -6,7 +6,6 @@ import com.google.common.collect.ImmutableListMultimap
 import com.google.common.collect.ListMultimap
 import com.openai.errors.OpenAIInvalidDataException
 import java.util.Collections
-import java.util.SortedMap
 
 @JvmSynthetic
 internal fun <T : Any> T?.getOrThrow(name: String): T =
@@ -20,11 +19,6 @@ internal fun <T> List<T>.toImmutable(): List<T> =
 internal fun <K, V> Map<K, V>.toImmutable(): Map<K, V> =
     if (isEmpty()) Collections.emptyMap() else Collections.unmodifiableMap(toMap())
 
-@JvmSynthetic
-internal fun <K : Comparable<K>, V> SortedMap<K, V>.toImmutable(): SortedMap<K, V> =
-    if (isEmpty()) Collections.emptySortedMap()
-    else Collections.unmodifiableSortedMap(toSortedMap(comparator()))
-
 @JvmSynthetic
 internal fun <K, V> ListMultimap<K, V>.toImmutable(): ListMultimap<K, V> =
     ImmutableListMultimap.copyOf(this)