Update serialization library version and improve comments

Author: devcrocod

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/io/readJson.kt

@@ -167,7 +167,7 @@ internal fun fromJsonListAnyColumns(
 
     @Suppress("KotlinConstantConditions")
     val columns: List<AnyCol> = when {
-        // Create one column of type Any? (or guessed a primitive type) from all the records
+        // Create one column of type Any? (or guessed primitive type) from all the records
         colType == AnyColType.ANY -> {
             val collector: DataCollectorBase<Any?> =
                 if (justPrimitives) createDataCollector(records.size) // guess the type
@@ -419,7 +419,7 @@ internal fun fromJsonListArrayAndValueColumns(
 
     // list element type can be JsonObject, JsonArray or primitive
     // So first, we gather all properties of objects to merge including "array" and "value" if needed
-    // so the resulting type of property with instances 123, ["abc"], and { "a": 1, "b": 2 } will be
+    // so the resulting type of a property with instances 123, ["abc"], and { "a": 1, "b": 2 } will be
     // { array: List<String>, value: Int?, a: Int?, b: Int? }
     // and instances will look like
     // { "array": [], "value": 123, "a": null, "b": null }

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/io/writeJson.kt

@@ -156,7 +156,6 @@ internal fun encodeRowWithMetadata(
         }.let { col.name to it }
     }
     if (values.isEmpty()) return null
-    JsonObject(mapOf("exampleKey" to JsonPrimitive("exampleValue")))
     return JsonObject(values.toMap())
 }
 

gradle/libs.versions.toml

@@ -26,7 +26,7 @@ kover = "0.6.1"
 
 commonsCsv = "1.10.0"
 commonsCompress = "1.26.0"
-serialization = "1.6.2"
+serialization = "1.7.0"
 fuel = "2.3.1"
 poi = "5.2.5"
 mariadb = "3.3.2"