diff --git a/build.gradle.kts b/build.gradle.kts
index 9a48fb23..dd159c0b 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
     id("org.jetbrains.dokka") version "0.10.1"
 }
 
-val dataforgeVersion by extra("0.1.8-dev-2")
+val dataforgeVersion by extra("0.1.8-dev-4")
 
 val bintrayRepo by extra("dataforge")
 val githubProject by extra("dataforge-core")
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
index 768ddbfa..f0e3725f 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Meta.kt
@@ -16,8 +16,12 @@ import kotlinx.serialization.*
 @Serializable
 sealed class MetaItem<out M : Meta> {
 
+    abstract override fun equals(other: Any?): Boolean
+
+    abstract override fun hashCode(): Int
+
     @Serializable
-    data class ValueItem(val value: Value) : MetaItem<Nothing>() {
+    class ValueItem(val value: Value) : MetaItem<Nothing>() {
         override fun toString(): String = value.toString()
 
         @Serializer(ValueItem::class)
@@ -30,10 +34,18 @@ sealed class MetaItem<out M : Meta> {
                 ValueSerializer.serialize(encoder, value.value)
             }
         }
+
+        override fun equals(other: Any?): Boolean {
+            return this.value == (other as? ValueItem)?.value
+        }
+
+        override fun hashCode(): Int {
+            return value.hashCode()
+        }
     }
 
     @Serializable
-    data class NodeItem<M : Meta>(@Serializable(MetaSerializer::class) val node: M) : MetaItem<M>() {
+    class NodeItem<M : Meta>(@Serializable(MetaSerializer::class) val node: M) : MetaItem<M>() {
         //Fixing serializer for node could cause class cast problems, but it should not since Meta descendants are not serializeable
         override fun toString(): String = node.toString()
 
@@ -47,6 +59,10 @@ sealed class MetaItem<out M : Meta> {
                 MetaSerializer.serialize(encoder, value.node)
             }
         }
+
+        override fun equals(other: Any?): Boolean = node == (other as? NodeItem<*>)?.node
+
+        override fun hashCode(): Int = node.hashCode()
     }
 
     companion object {
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/Described.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/Described.kt
index 0a09a0fb..ac8ba74a 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/Described.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/descriptors/Described.kt
@@ -4,7 +4,7 @@ package hep.dataforge.meta.descriptors
  * An object which provides its descriptor
  */
 interface Described {
-    val descriptor: NodeDescriptor?
+    val descriptor: ItemDescriptor?
 
     companion object {
         const val DESCRIPTOR_NODE = "@descriptor"
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/transformations/MetaCaster.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/transformations/MetaConverter.kt
similarity index 76%
rename from dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/transformations/MetaCaster.kt
rename to dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/transformations/MetaConverter.kt
index 21785980..bd967a85 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/transformations/MetaCaster.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/transformations/MetaConverter.kt
@@ -9,13 +9,18 @@ import hep.dataforge.values.*
 /**
  * A converter of generic object to and from [MetaItem]
  */
-interface MetaCaster<T : Any> {
+interface MetaConverter<T : Any> {
     fun itemToObject(item: MetaItem<*>): T
     fun objectToMetaItem(obj: T): MetaItem<*>
 
     companion object {
 
-        val meta = object : MetaCaster<Meta> {
+        val item = object :MetaConverter<MetaItem<*>>{
+            override fun itemToObject(item: MetaItem<*>): MetaItem<*> = item
+            override fun objectToMetaItem(obj: MetaItem<*>): MetaItem<*> = obj
+        }
+
+        val meta = object : MetaConverter<Meta> {
             override fun itemToObject(item: MetaItem<*>): Meta = when (item) {
                 is MetaItem.NodeItem -> item.node
                 is MetaItem.ValueItem -> item.value.toMeta()
@@ -24,7 +29,7 @@ interface MetaCaster<T : Any> {
             override fun objectToMetaItem(obj: Meta): MetaItem<*> = MetaItem.NodeItem(obj)
         }
 
-        val value = object : MetaCaster<Value> {
+        val value = object : MetaConverter<Value> {
             override fun itemToObject(item: MetaItem<*>): Value = when (item) {
                 is MetaItem.NodeItem -> item.node[Meta.VALUE_KEY].value ?: error("Can't convert node to a value")
                 is MetaItem.ValueItem -> item.value
@@ -33,7 +38,7 @@ interface MetaCaster<T : Any> {
             override fun objectToMetaItem(obj: Value): MetaItem<*> = MetaItem.ValueItem(obj)
         }
 
-        val string = object : MetaCaster<String> {
+        val string = object : MetaConverter<String> {
             override fun itemToObject(item: MetaItem<*>): String = when (item) {
                 is MetaItem.NodeItem -> item.node[Meta.VALUE_KEY].value ?: error("Can't convert node to a value")
                 is MetaItem.ValueItem -> item.value
@@ -42,7 +47,7 @@ interface MetaCaster<T : Any> {
             override fun objectToMetaItem(obj: String): MetaItem<*> = MetaItem.ValueItem(obj.asValue())
         }
 
-        val boolean = object : MetaCaster<Boolean> {
+        val boolean = object : MetaConverter<Boolean> {
             override fun itemToObject(item: MetaItem<*>): Boolean = when (item) {
                 is MetaItem.NodeItem -> item.node[Meta.VALUE_KEY].value ?: error("Can't convert node to a value")
                 is MetaItem.ValueItem -> item.value
@@ -51,7 +56,7 @@ interface MetaCaster<T : Any> {
             override fun objectToMetaItem(obj: Boolean): MetaItem<*> = MetaItem.ValueItem(obj.asValue())
         }
 
-        val double = object : MetaCaster<Double> {
+        val double = object : MetaConverter<Double> {
             override fun itemToObject(item: MetaItem<*>): Double = when (item) {
                 is MetaItem.NodeItem -> item.node[Meta.VALUE_KEY].value ?: error("Can't convert node to a value")
                 is MetaItem.ValueItem -> item.value
@@ -60,7 +65,7 @@ interface MetaCaster<T : Any> {
             override fun objectToMetaItem(obj: Double): MetaItem<*> = MetaItem.ValueItem(obj.asValue())
         }
 
-        val int = object : MetaCaster<Int> {
+        val int = object : MetaConverter<Int> {
             override fun itemToObject(item: MetaItem<*>): Int = when (item) {
                 is MetaItem.NodeItem -> item.node[Meta.VALUE_KEY].value ?: error("Can't convert node to a value")
                 is MetaItem.ValueItem -> item.value
@@ -71,5 +76,5 @@ interface MetaCaster<T : Any> {
     }
 }
 
-fun <T : Any> MetaCaster<T>.metaToObject(meta: Meta): T = itemToObject(MetaItem.NodeItem(meta))
-fun <T : Any> MetaCaster<T>.valueToObject(value: Value): T = itemToObject(MetaItem.ValueItem(value))
+fun <T : Any> MetaConverter<T>.metaToObject(meta: Meta): T = itemToObject(MetaItem.NodeItem(meta))
+fun <T : Any> MetaConverter<T>.valueToObject(value: Value): T = itemToObject(MetaItem.ValueItem(value))