Java Code for creating child elements within an element - xsd

Question

I want to generate the following XSD Schema using JAXB and ObjectFactory class of org/w3/_2001/xmlschema
<xs:element name="result">
<xs:complexType>
<xs:sequence>
<xs:element name="sfobject" maxOccurs="unbounded" minOccurs="0">
<xs:complexType>
<xs:sequence>
<xs:element type="xs:string" name="id"/>
<xs:element type="xs:string" name="type"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
But I am getting XSD as :
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="result">
<xs:complexType>
<xs:sequence/>
</xs:complexType>
</xs:element>
<xs:element name="sfobject" maxOccurs="unbounded" minOccurs="0">
<xs:complexType>
<xs:sequence/>
</xs:complexType>
</xs:element>
<xs:element type="xs:string" name="id"/>
<xs:element type="xs:string" name="type"/>
</xs:schema>
I am not able to add one element inside other element. How do I do that in Java using JAXB and ObjectFactory methods.
Sample Code:
List schemaElementList = schema.getSimpleTypeOrComplexTypeOrGroup();
TopLevelElement resultElement = xsdObjFactory.createTopLevelElement();
resultElement.setName("result");
LocalComplexType resultCompType = xsdObjFactory.createLocalComplexType();
resultElement.setComplexType(resultCompType);
resultCompType.setSequence(expGroup);
Element sfElement = (Element)xsdObjFactory.createLocalElement();
sfElement.setName("sfobject");
sfElement.setMaxOccurs("unbounded");
sfElement.setMinOccurs(new BigInteger("0"));
LocalComplexType sfCompType = xsdObjFactory.createLocalComplexType();
sfElement.setComplexType(sfCompType);
schemaElementList.add(resultElement);