Default namespace issue- Need to understand on xmlns removal from 4.0 framework

Just executed the above code in my system but i dont see the default namespace like xmlns="http://www.w3.org/2001/XMLSchema"> i am getting below output.

<?xml version="1.0" encoding="IBM437"?>
<xs:schema xmlns:myImpPrefix="myImportNamespace" targetNamespace="myNamespace" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:import schemaLocation="http://www.example.com/myImportNamespace" namespace="myImportNamespace" />
<xs:element name="element1" type="myImpPrefix:importType" />
</xs:schema> xmlns="http://www.w3.org/2001/XMLSchema">

Looks like defaultnamepace is missing. Is there something has changed related to Defaultnamespace.?

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* ID: 9a645e0e-11f5-6dc6-4f6e-113b3af9e78d
* Version Independent ID: b0934b99-b88e-639f-14cd-2aa6f66453f8
* Content: [XmlSchemaObject.Namespaces Property (System.Xml.Schema)](https://docs.microsoft.com/en-us/dotnet/api/system.xml.schema.xmlschemaobject.namespaces?view=netframework-4.6.1#examples)
* Content Source: [xml/System.Xml.Schema/XmlSchemaObject.xml](https://github.com/dotnet/dotnet-api-docs/blob/master/xml/System.Xml.Schema/XmlSchemaObject.xml)
* Product: **dotnet-api**
* GitHub Login: @dotnet-bot
* Microsoft Alias: **dotnetcontent**