diff --git a/.idea/AndroidProjectSystem.xml b/.idea/AndroidProjectSystem.xml
new file mode 100644
index 00000000..4a53bee8
--- /dev/null
+++ b/.idea/AndroidProjectSystem.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="AndroidProjectSystem">
+    <option name="providerId" value="com.android.tools.idea.GradleProjectSystem" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/kotlinc.xml b/.idea/kotlinc.xml
index 98dd9bb5..52631507 100644
--- a/.idea/kotlinc.xml
+++ b/.idea/kotlinc.xml
@@ -7,6 +7,6 @@
     <option name="jvmTarget" value="1.8" />
   </component>
   <component name="KotlinJpsPluginSettings">
-    <option name="version" value="2.0.20" />
+    <option name="version" value="2.1.20" />
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/runConfigurations.xml b/.idea/runConfigurations.xml
index 931b96c3..16660f1d 100644
--- a/.idea/runConfigurations.xml
+++ b/.idea/runConfigurations.xml
@@ -5,8 +5,12 @@
       <set>
         <option value="com.intellij.execution.junit.AbstractAllInDirectoryConfigurationProducer" />
         <option value="com.intellij.execution.junit.AllInPackageConfigurationProducer" />
+        <option value="com.intellij.execution.junit.PatternConfigurationProducer" />
         <option value="com.intellij.execution.junit.TestInClassConfigurationProducer" />
         <option value="com.intellij.execution.junit.UniqueIdConfigurationProducer" />
+        <option value="com.intellij.execution.junit.testDiscovery.JUnitTestDiscoveryConfigurationProducer" />
+        <option value="org.jetbrains.kotlin.idea.junit.KotlinJUnitRunConfigurationProducer" />
+        <option value="org.jetbrains.kotlin.idea.junit.KotlinPatternConfigurationProducer" />
       </set>
     </option>
   </component>
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
index 4bf808cb..7ddfc9ed 100644
--- a/.idea/vcs.xml
+++ b/.idea/vcs.xml
@@ -3,8 +3,6 @@
   <component name="CommitMessageInspectionProfile">
     <profile version="1.0">
       <inspection_tool class="CommitFormat" enabled="true" level="WARNING" enabled_by_default="true" />
-      <inspection_tool class="CommitFormat" enabled="true" level="WARNING" enabled_by_default="true" />
-      <inspection_tool class="CommitNamingConvention" enabled="true" level="WARNING" enabled_by_default="true" />
       <inspection_tool class="CommitNamingConvention" enabled="true" level="WARNING" enabled_by_default="true" />
     </profile>
   </component>
diff --git a/buildSrc/gradle/wrapper/gradle-wrapper.jar b/buildSrc/gradle/wrapper/gradle-wrapper.jar
index a4b76b95..9bbc975c 100644
Binary files a/buildSrc/gradle/wrapper/gradle-wrapper.jar and b/buildSrc/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/core/src/main/java/com/hoc/flowmvi/core/EitherNes.kt b/core/src/main/java/com/hoc/flowmvi/core/EitherNes.kt
index 0cd43881..0f8af29c 100644
--- a/core/src/main/java/com/hoc/flowmvi/core/EitherNes.kt
+++ b/core/src/main/java/com/hoc/flowmvi/core/EitherNes.kt
@@ -1,9 +1,11 @@
 package com.hoc.flowmvi.core
 
 import arrow.core.Either
+import arrow.core.NonEmptySet
 import arrow.core.left
+import arrow.core.nonEmptySetOf
 import arrow.core.right
-import com.hoc.flowmvi.core.NonEmptySet.Companion.toNonEmptySetOrNull
+import arrow.core.toNonEmptySetOrNull
 import kotlin.contracts.ExperimentalContracts
 import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
@@ -17,7 +19,7 @@ typealias EitherNes<E, A> = Either<NonEmptySet<E>, A>
 inline fun <A> A.rightNes(): EitherNes<Nothing, A> = this.right()
 
 @Suppress("NOTHING_TO_INLINE")
-inline fun <E> E.leftNes(): EitherNes<E, Nothing> = NonEmptySet.of(this).left()
+inline fun <E> E.leftNes(): EitherNes<E, Nothing> = nonEmptySetOf(this).left()
 
 @OptIn(ExperimentalContracts::class)
 inline fun <E, A, B, C, Z> Either.Companion.zipOrAccumulateNonEmptySet(
diff --git a/core/src/main/java/com/hoc/flowmvi/core/NonEmptySet.kt b/core/src/main/java/com/hoc/flowmvi/core/NonEmptySet.kt
deleted file mode 100644
index 315af8b8..00000000
--- a/core/src/main/java/com/hoc/flowmvi/core/NonEmptySet.kt
+++ /dev/null
@@ -1,70 +0,0 @@
-package com.hoc.flowmvi.core
-
-/**
- * `NonEmptySet` is a data type used to model sets that guarantee to have at least one value.
- */
-class NonEmptySet<out T>
-  @Throws(IllegalArgumentException::class)
-  private constructor(
-    val set: Set<T>,
-  ) : AbstractSet<T>() {
-    init {
-      require(set.isNotEmpty()) { "Set must not be empty" }
-      require(set !is NonEmptySet<T>) { "Set must not be NonEmptySet" }
-    }
-
-    override val size: Int get() = set.size
-
-    override fun iterator(): Iterator<T> = set.iterator()
-
-    override fun isEmpty(): Boolean = false
-
-    operator fun plus(l: NonEmptySet<@UnsafeVariance T>): NonEmptySet<T> = NonEmptySet(set + l.set)
-
-    @Suppress("RedundantOverride")
-    override fun equals(other: Any?): Boolean = super.equals(other)
-
-    @Suppress("RedundantOverride")
-    override fun hashCode(): Int = super.hashCode()
-
-    override fun toString(): String = "NonEmptySet(${set.joinToString()})"
-
-    companion object {
-      /**
-       * Creates a [NonEmptySet] from the given [Collection].
-       * @return null if [this] is empty.
-       */
-      @JvmStatic
-      fun <T> Collection<T>.toNonEmptySetOrNull(): NonEmptySet<T>? = if (isEmpty()) null else NonEmptySet(toSet())
-
-      /**
-       * Creates a [NonEmptySet] from the given [Set].
-       * @return null if [this] is empty.
-       */
-      @JvmStatic
-      fun <T> Set<T>.toNonEmptySetOrNull(): NonEmptySet<T>? =
-        (this as? NonEmptySet<T>)
-          ?: if (isEmpty()) null else NonEmptySet(this)
-
-      /**
-       * Creates a [NonEmptySet] from the given values.
-       */
-      @JvmStatic
-      fun <T> of(
-        element: T,
-        vararg elements: T,
-      ): NonEmptySet<T> =
-        NonEmptySet(
-          buildSet(capacity = 1 + elements.size) {
-            add(element)
-            addAll(elements)
-          },
-        )
-
-      /**
-       * Creates a [NonEmptySet] that contains only the specified [element].
-       */
-      @JvmStatic
-      fun <T> of(element: T): NonEmptySet<T> = NonEmptySet(setOf(element))
-    }
-  }
diff --git a/core/src/test/java/com/hoc/flowmvi/core/NonEmptySetTest.kt b/core/src/test/java/com/hoc/flowmvi/core/NonEmptySetTest.kt
deleted file mode 100644
index 040bfc12..00000000
--- a/core/src/test/java/com/hoc/flowmvi/core/NonEmptySetTest.kt
+++ /dev/null
@@ -1,156 +0,0 @@
-package com.hoc.flowmvi.core
-
-import com.hoc.flowmvi.core.NonEmptySet.Companion.toNonEmptySetOrNull
-import kotlin.test.Test
-import kotlin.test.assertEquals
-import kotlin.test.assertNotNull
-import kotlin.test.assertNull
-import kotlin.test.assertSame
-
-class NonEmptySetTest {
-  @Test
-  fun `test List#toNonEmptySetOrNull returns null when input is empty`() {
-    assertNull(emptyList<Int>().toNonEmptySetOrNull())
-  }
-
-  @Test
-  fun `test List#toNonEmptySetOrNull returns NonEmptySet when input is not empty`() {
-    assertEquals(
-      setOf(1),
-      assertNotNull(
-        listOf(1).toNonEmptySetOrNull(),
-      ),
-    )
-
-    assertEquals(
-      setOf(1, 2),
-      assertNotNull(
-        listOf(1, 2).toNonEmptySetOrNull(),
-      ),
-    )
-
-    assertEquals(
-      setOf(1),
-      assertNotNull(
-        listOf(1, 1).toNonEmptySetOrNull(),
-      ),
-    )
-  }
-
-  @Test
-  fun `test Set#toNonEmptySetOrNull returns null when input is empty`() {
-    assertNull(emptySet<Int>().toNonEmptySetOrNull())
-  }
-
-  @Test
-  fun `test Set#toNonEmptySetOrNull returns NonEmptySet when input is not empty`() {
-    assertEquals(
-      setOf(1),
-      assertNotNull(
-        setOf(1).toNonEmptySetOrNull(),
-      ),
-    )
-
-    assertEquals(
-      setOf(1, 2),
-      assertNotNull(
-        setOf(1, 2).toNonEmptySetOrNull(),
-      ),
-    )
-
-    assertEquals(
-      setOf(1),
-      assertNotNull(
-        setOf(1, 1).toNonEmptySetOrNull(),
-      ),
-    )
-  }
-
-  @Test
-  fun `test Set#toNonEmptySetOrNull returns itself when the input is NonEmptySet`() {
-    val input = NonEmptySet.of(1)
-
-    assertSame(
-      input,
-      input.toNonEmptySetOrNull(),
-    )
-  }
-
-  @Test
-  fun `test NonEmptySet#of`() {
-    assertEquals(
-      setOf(1),
-      NonEmptySet.of(1),
-    )
-
-    assertEquals(
-      setOf(1, 2),
-      NonEmptySet.of(1, 2),
-    )
-
-    assertEquals(
-      setOf(1),
-      NonEmptySet.of(1, 1),
-    )
-  }
-
-  @Test
-  fun `test NonEmptySet#equals`() {
-    assertEquals(
-      NonEmptySet.of(1),
-      NonEmptySet.of(1),
-    )
-    assertEquals(
-      NonEmptySet.of(1, 2),
-      NonEmptySet.of(1, 2),
-    )
-    assertEquals(
-      NonEmptySet.of(1, 1),
-      NonEmptySet.of(1, 1),
-    )
-
-    assertEquals(
-      listOf(1, 2).toNonEmptySetOrNull(),
-      listOf(1, 2).toNonEmptySetOrNull(),
-    )
-
-    assertEquals(
-      hashSetOf(1, 2).toNonEmptySetOrNull(),
-      linkedSetOf(1, 2).toNonEmptySetOrNull(),
-    )
-    assertEquals(
-      setOf(1, 2).toNonEmptySetOrNull(),
-      setOf(1, 2).toNonEmptySetOrNull(),
-    )
-  }
-
-  @Test
-  fun `test NonEmptySet#hashCode`() {
-    assertEquals(
-      NonEmptySet.of(1).hashCode(),
-      NonEmptySet.of(1).hashCode(),
-    )
-    assertEquals(
-      NonEmptySet.of(1, 2).hashCode(),
-      NonEmptySet.of(1, 2).hashCode(),
-    )
-    assertEquals(
-      NonEmptySet.of(1, 1).hashCode(),
-      NonEmptySet.of(1, 1).hashCode(),
-    )
-
-    assertEquals(
-      listOf(1, 2).toNonEmptySetOrNull()!!.hashCode(),
-      listOf(1, 2).toNonEmptySetOrNull()!!.hashCode(),
-    )
-
-    assertEquals(
-      hashSetOf(1, 2).toNonEmptySetOrNull()!!.hashCode(),
-      linkedSetOf(1, 2).toNonEmptySetOrNull()!!.hashCode(),
-    )
-    assertEquals(
-      setOf(1, 2).toNonEmptySetOrNull()!!.hashCode(),
-      setOf(1, 2).toNonEmptySetOrNull()!!.hashCode(),
-    )
-  }
-}
diff --git a/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt b/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt
index 489308fd..27b7844d 100644
--- a/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt
+++ b/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt
@@ -1,6 +1,6 @@
 package com.hoc.flowmvi.data.mapper
 
-import com.hoc.flowmvi.core.NonEmptySet
+import arrow.core.nonEmptySetOf
 import com.hoc.flowmvi.data.remote.ErrorResponse
 import com.hoc.flowmvi.domain.model.UserError
 import com.hoc.flowmvi.domain.model.UserValidationError
@@ -55,8 +55,8 @@ class UserErrorMapperTest {
     assertEquals(UserError.UserNotFound("1"), errorMapper(UserError.UserNotFound("1")))
     assertEquals(UserError.InvalidId("1"), errorMapper(UserError.InvalidId("1")))
     assertEquals(
-      UserError.ValidationFailed(NonEmptySet.of(UserValidationError.INVALID_EMAIL_ADDRESS)),
-      errorMapper(UserError.ValidationFailed(NonEmptySet.of(UserValidationError.INVALID_EMAIL_ADDRESS))),
+      UserError.ValidationFailed(nonEmptySetOf(UserValidationError.INVALID_EMAIL_ADDRESS)),
+      errorMapper(UserError.ValidationFailed(nonEmptySetOf(UserValidationError.INVALID_EMAIL_ADDRESS))),
     )
     assertEquals(UserError.ServerError, errorMapper(UserError.ServerError))
     assertEquals(UserError.Unexpected, errorMapper(UserError.Unexpected))
diff --git a/domain/src/main/java/com/hoc/flowmvi/domain/model/UserError.kt b/domain/src/main/java/com/hoc/flowmvi/domain/model/UserError.kt
index d3c075b2..9d869352 100644
--- a/domain/src/main/java/com/hoc/flowmvi/domain/model/UserError.kt
+++ b/domain/src/main/java/com/hoc/flowmvi/domain/model/UserError.kt
@@ -1,9 +1,11 @@
 package com.hoc.flowmvi.domain.model
 
-import com.hoc.flowmvi.core.NonEmptySet
+import arrow.core.NonEmptySet
 
 sealed class UserError : Throwable() {
-  object NetworkError : UserError()
+  data object NetworkError : UserError() {
+    private fun readResolve(): Any = NetworkError
+  }
 
   data class UserNotFound(
     val id: String,
@@ -16,6 +18,12 @@ sealed class UserError : Throwable() {
   data class ValidationFailed(
     val errors: NonEmptySet<UserValidationError>,
   ) : UserError()
-  object ServerError : UserError()
-  object Unexpected : UserError()
+
+  data object ServerError : UserError() {
+    private fun readResolve(): Any = ServerError
+  }
+
+  data object Unexpected : UserError() {
+    private fun readResolve(): Any = Unexpected
+  }
 }
diff --git a/domain/src/main/java/com/hoc/flowmvi/domain/model/UserValidationError.kt b/domain/src/main/java/com/hoc/flowmvi/domain/model/UserValidationError.kt
index 623b6838..fca19b3e 100644
--- a/domain/src/main/java/com/hoc/flowmvi/domain/model/UserValidationError.kt
+++ b/domain/src/main/java/com/hoc/flowmvi/domain/model/UserValidationError.kt
@@ -1,8 +1,8 @@
 package com.hoc.flowmvi.domain.model
 
+import arrow.core.NonEmptySet
+import arrow.core.toNonEmptySetOrNull
 import com.hoc.flowmvi.core.EitherNes
-import com.hoc.flowmvi.core.NonEmptySet
-import com.hoc.flowmvi.core.NonEmptySet.Companion.toNonEmptySetOrNull
 import com.hoc.flowmvi.core.leftNes
 
 enum class UserValidationError {
@@ -14,14 +14,6 @@ enum class UserValidationError {
   val asLeftNes: EitherNes<UserValidationError, Nothing> = leftNes()
 
   companion object {
-    /**
-     * Use this instead of [values()] for more performant.
-     * See [KT-48872](https://youtrack.jetbrains.com/issue/KT-48872)
-     */
-    @JvmField
-    val VALUES: List<UserValidationError> = values().asList()
-
-    @JvmField
-    val VALUES_SET: NonEmptySet<UserValidationError> = VALUES.toNonEmptySetOrNull()!!
+    val VALUES_SET: NonEmptySet<UserValidationError> = UserValidationError.entries.toNonEmptySetOrNull()!!
   }
 }