#it xml & xsd

<?xml version="1.0" encoding="UTF-8" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="locker">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="boxSmall" minOccurs="3" maxOccurs="3">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="objectSmall" minOccurs="0" maxOccurs="5">
                                <xs:complexType>
                                    <xs:choice>
                                        <xs:element name="book" minOccurs="0">
                                            <xs:complexType>
                                                <xs:attribute name="author" type="xs:string" />
                                                <xs:attribute name="title" type="xs:string" />
                                            </xs:complexType>
                                        </xs:element>
                                        <xs:element name="other" minOccurs="0">
                                            <xs:complexType>
                                                <xs:attribute name="object" type="xs:string" />
                                            </xs:complexType>
                                        </xs:element>
                                    </xs:choice>
                                </xs:complexType>
                            </xs:element>
                            <xs:element name="objectLarge" minOccurs="0" maxOccurs="1">
                                <xs:complexType>
                                    <xs:sequence>
                                        <xs:element name="other" minOccurs="1">
                                            <xs:complexType>
                                                <xs:attribute name="object" type="xs:string" />
                                            </xs:complexType>
                                        </xs:element>
                                    </xs:sequence>
                                </xs:complexType>
                            </xs:element>
                         </xs:sequence>
                       <xs:attribute name="state" type="xs:string" use="required"/>
                    </xs:complexType>
                </xs:element>
                <xs:element name="boxLarge" minOccurs="1" maxOccurs="1">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="objectSmall" minOccurs="0" maxOccurs="10">
                                <xs:complexType>
                                    <xs:choice>
                                        <xs:element name="book" minOccurs="0">
                                            <xs:complexType>
                                                <xs:attribute name="author" type="xs:string" />
                                                <xs:attribute name="title" type="xs:string" />
                                            </xs:complexType>
                                        </xs:element>
                                        <xs:element name="other" minOccurs="0">
                                            <xs:complexType>
                                                <xs:attribute name="object" type="xs:string" />
                                            </xs:complexType>
                                        </xs:element>
                                    </xs:choice>
                                </xs:complexType>
                            </xs:element>
                            <xs:element name="objectLarge" minOccurs="0" maxOccurs="3">
                                <xs:complexType>
                                    <xs:sequence>
                                        <xs:element name="other" minOccurs="1">
                                            <xs:complexType>
                                                <xs:attribute name="object" type="xs:string" />
                                            </xs:complexType>
                                        </xs:element>
                                    </xs:sequence>
                                </xs:complexType>
                            </xs:element>
                         </xs:sequence>
                       <xs:attribute name="state" type="xs:string" use="required"/>
                    </xs:complexType>
                </xs:element>
            </xs:sequence>
            <xs:attribute name="owner" type="xs:string" use="required"/>
        </xs:complexType>
    </xs:element>
</xs:schema>



<?xml version="1.0" encoding="UTF-8" ?>
<locker owner="abelyaev">
    <boxSmall state="open">
        <objectSmall>
            <book author="george r.r. martin" title="the game of thrones"/>
        </objectSmall>
        <objectSmall>
            <book author="hebert wells" title="the invisible man"/>
        </objectSmall>
        <objectSmall>
            <other object="mug"/>
        </objectSmall>
        <objectLarge>
            <other object="bag"/>
        </objectLarge>
    </boxSmall>
    <boxSmall state="open"/>
    <boxSmall state="open"/>
    <boxLarge state="closed">
        <objectSmall>
            <book author="geroge orwell"/>
        </objectSmall>
        <objectSmall>
            <other object="notpad"></other>
        </objectSmall>
        <objectSmall>
            <book/>
        </objectSmall>
        <objectLarge>
            <other object="stone"/>
        </objectLarge>
    </boxLarge>
</locker>