public class wwwTheyukicompanyCom1 {
    public class ProcessSalesInvoicesResponse_element {
        public wwwTheyukicompanyCom1.ProcessSalesInvoicesResult_element ProcessSalesInvoicesResult;
        private String[] ProcessSalesInvoicesResult_type_info = new String[]{'ProcessSalesInvoicesResult','http://www.theyukicompany.com/',null,'0','1','false'};
        private String[] apex_schema_type_info = new String[]{'http://www.theyukicompany.com/','true','false'};
        private String[] field_order_type_info = new String[]{'ProcessSalesInvoicesResult'};
    }
    public class ProcessSalesInvoices_element {
        public String sessionId;
        public String administrationId;
        public wwwTheyukicompanyCom1.xmlDoc_element xmlDoc;
        private String[] sessionId_type_info = new String[]{'sessionId','http://www.theyukicompany.com/',null,'0','1','false'};
        private String[] administrationId_type_info = new String[]{'administrationId','http://www.theyukicompany.com/',null,'0','1','false'};
        private String[] xmlDoc_type_info = new String[]{'xmlDoc','http://www.theyukicompany.com/',null,'0','1','false'};
        private String[] apex_schema_type_info = new String[]{'http://www.theyukicompany.com/','true','false'};
        private String[] field_order_type_info = new String[]{'sessionId','administrationId','xmlDoc'};
    }
    public class ProcessSalesInvoicesResult_element {
        private String[] apex_schema_type_info = new String[]{'http://www.theyukicompany.com/','true','false'};
        private String[] field_order_type_info = new String[]{};
    }
    public class xmlDoc_element {
        private String[] apex_schema_type_info = new String[]{'http://www.theyukicompany.com/','true','false'};
        private String[] field_order_type_info = new String[]{};
    }
    public class SalesSoap {
        public String endpoint_x = 'http://api.yukiworks.nl/ws/Sales.asmx';
        public Map<String,String> inputHttpHeaders_x;
        public Map<String,String> outputHttpHeaders_x;
        public String clientCertName_x;
        public String clientCert_x;
        public String clientCertPasswd_x;
        public Integer timeout_x;
        private String[] ns_map_type_info = new String[]{'http://www.theyukicompany.com/', 'wwwTheyukicompanyCom1'};
        public wwwTheyukicompanyCom1.ProcessSalesInvoicesResult_element ProcessSalesInvoices(String sessionId,String administrationId,wwwTheyukicompanyCom1.xmlDoc_element xmlDoc) {
            wwwTheyukicompanyCom1.ProcessSalesInvoices_element request_x = new wwwTheyukicompanyCom1.ProcessSalesInvoices_element();
            request_x.sessionId = sessionId;
            request_x.administrationId = administrationId;
            request_x.xmlDoc = xmlDoc;
            wwwTheyukicompanyCom1.ProcessSalesInvoicesResponse_element response_x;
            Map<String, wwwTheyukicompanyCom1.ProcessSalesInvoicesResponse_element> response_map_x = new Map<String, wwwTheyukicompanyCom1.ProcessSalesInvoicesResponse_element>();
            response_map_x.put('response_x', response_x);
            WebServiceCallout.invoke(
              this,
              request_x,
              response_map_x,
              new String[]{endpoint_x,
              'http://www.theyukicompany.com/ProcessSalesInvoices',
              'http://www.theyukicompany.com/',
              'ProcessSalesInvoices',
              'http://www.theyukicompany.com/',
              'ProcessSalesInvoicesResponse',
              'wwwTheyukicompanyCom1.ProcessSalesInvoicesResponse_element'}
            );
            response_x = response_map_x.get('response_x');
            return response_x.ProcessSalesInvoicesResult;
        }
    }
}

wwwTheyukicompanyCom1.SalesSoap s = new wwwTheyukicompanyCom1.SalesSoap();
wwwTheyukicompanyCom1.xmlDoc_element xmldoc = new wwwTheyukicompanyCom1.xmlDoc_element();
s.ProcessSalesInvoices('','',xmldoc);

public class xmlDoc_element {
    private String[] apex_schema_type_info = new String[]{'http://www.theyukicompany.com/','true','false'};
    private String[] field_order_type_info = new String[]{'*'};
}