diff --git a/src/test/java/org/mustangproject/ZUGFeRD/BackwardCompatibilityTest.java b/src/test/java/org/mustangproject/ZUGFeRD/BackwardCompatibilityTest.java
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index 00000000..f8fef6a9
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+++ b/src/test/java/org/mustangproject/ZUGFeRD/BackwardCompatibilityTest.java
@@ -0,0 +1,432 @@
+/** **********************************************************************
+ *
+ * Copyright 2019 Jochen Staerk
+ *
+ * Use is subject to license terms.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ *********************************************************************** */
+package org.mustangproject.ZUGFeRD;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigDecimal;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.GregorianCalendar;
+
+import junit.framework.TestCase;
+
+/***
+ * This is a test to confirm the minimum steps to implement a interface are still sufficient
+ * 
+ * @author jstaerk
+ *
+ */
+public class BackwardCompatibilityTest extends TestCase implements IZUGFeRDExportableTransaction{
+
+	final String TARGET_PDF_ZF1 = "./target/testout-MustangGnuaccountingBeispielRE-20171118_506zf1.pdf";
+	final String TARGET_PDF_ZF2 = "./target/testout-MustangGnuaccountingBeispielRE-20171118_506zf2.pdf";
+	final String TARGET_PDF_FX = "./target/testout-MustangGnuaccountingBeispielRE-20171118_506fx.pdf";
+
+	/**
+	 * The exporter test bases on @{code
+	 * ./src/test/MustangGnuaccountingBeispielRE-20140703_502blanko.pdf}, adds
+	 * metadata, writes to @{code ./target/testout-*} and then imports to check the
+	 * values. It would not make sense to have it run before the less complex
+	 * importer test (which is probably redundant). As only Name Ascending is
+	 * supported for Test Unit sequence, I renamed the Exporter Test test-Z-Export
+	 */
+	public void testZF1Export() {
+
+
+		// the writing part
+		try (InputStream SOURCE_PDF = this.getClass()
+			.getResourceAsStream("/MustangGnuaccountingBeispielRE-20190610_507blanko.pdf");
+
+			 ZUGFeRDExporter ze = new ZUGFeRDExporterFromA1Factory().setZUGFeRDVersion(1).setZUGFeRDConformanceLevel(ZUGFeRDConformanceLevel.EN16931).load(SOURCE_PDF)) {
+
+			ze.PDFattachZugferdFile(this);
+			ze.disableAutoClose(true);
+			ze.export(TARGET_PDF_ZF1);
+
+			ByteArrayOutputStream baos = new ByteArrayOutputStream();
+			ze.export(baos);
+			ze.close();
+			String pdfContent = baos.toString("UTF-8");
+			assertFalse(pdfContent.indexOf("(via mustangproject.org") == -1);
+			// check for pdf-a schema extension
+//			assertFalse(pdfContent.indexOf("<zf:ConformanceLevel>EN 16931</zf:ConformanceLevel>") == -1);
+//			assertFalse(pdfContent.indexOf("<pdfaSchema:prefix>zf</pdfaSchema:prefix>") == -1);
+//			assertFalse(pdfContent.indexOf("urn:zugferd:pdfa:CrossIndustryDocument:invoice:2p0#") == -1);
+
+		} catch (IOException e) {
+			fail("IOException should not happen in testZExport");
+		}
+
+		// now check the contents (like MustangReaderTest)
+		ZUGFeRDImporter zi = new ZUGFeRDImporter(TARGET_PDF_ZF1);
+
+		// Reading ZUGFeRD
+		assertEquals(zi.getAmount(), "571.04");
+		assertEquals(zi.getBIC(), getTradeSettlementPayment()[0].getOwnBIC());
+		assertEquals(zi.getIBAN(), getTradeSettlementPayment()[0].getOwnIBAN());
+		assertEquals(zi.getHolder(), getOwnOrganisationName());
+		assertEquals(zi.getForeignReference(), getNumber());
+		
+		
+	}
+
+	public void testZF2Export() {
+
+	
+		// the writing part
+		try (InputStream SOURCE_PDF = this.getClass()
+			.getResourceAsStream("/MustangGnuaccountingBeispielRE-20190610_507blanko.pdf");
+
+			 ZUGFeRDExporter ze = new ZUGFeRDExporterFromA1Factory().setZUGFeRDVersion(2).setZUGFeRDConformanceLevel(ZUGFeRDConformanceLevel.EN16931).load(SOURCE_PDF)) {
+
+			ze.PDFattachZugferdFile(this);
+			ze.disableAutoClose(true);
+			ze.export(TARGET_PDF_ZF2);
+
+			ByteArrayOutputStream baos = new ByteArrayOutputStream();
+			ze.export(baos);
+			ze.close();
+			String pdfContent = baos.toString("UTF-8");
+			assertFalse(pdfContent.indexOf("(via mustangproject.org") == -1);
+			// check for pdf-a schema extension
+//			assertFalse(pdfContent.indexOf("<zf:ConformanceLevel>EN 16931</zf:ConformanceLevel>") == -1);
+//			assertFalse(pdfContent.indexOf("<pdfaSchema:prefix>zf</pdfaSchema:prefix>") == -1);
+//			assertFalse(pdfContent.indexOf("urn:zugferd:pdfa:CrossIndustryDocument:invoice:2p0#") == -1);
+
+		} catch (IOException e) {
+			fail("IOException should not happen in testZExport");
+		}
+
+		// now check the contents (like MustangReaderTest)
+		ZUGFeRDImporter zi = new ZUGFeRDImporter(TARGET_PDF_ZF2);
+
+		// Reading ZUGFeRD
+		assertEquals(zi.getAmount(), "571.04");
+		assertEquals(zi.getBIC(), getTradeSettlementPayment()[0].getOwnBIC());
+		assertEquals(zi.getIBAN(), getTradeSettlementPayment()[0].getOwnIBAN());
+		assertEquals(zi.getHolder(), getOwnOrganisationName());
+		assertEquals(zi.getForeignReference(), getNumber());
+		
+		
+	}
+	public void testFXExport() {
+
+		// the writing part
+		try (InputStream SOURCE_PDF = this.getClass()
+			.getResourceAsStream("/MustangGnuaccountingBeispielRE-20190610_507blanko.pdf");
+
+			 ZUGFeRDExporter ze = new ZUGFeRDExporterFromA1Factory().setZUGFeRDVersion(2).setZUGFeRDConformanceLevel(ZUGFeRDConformanceLevel.EN16931).load(SOURCE_PDF)) {
+
+			ze.setFacturX();
+			ze.PDFattachZugferdFile(this);
+			ze.disableAutoClose(true);
+			ze.export(TARGET_PDF_FX);
+
+			ByteArrayOutputStream baos = new ByteArrayOutputStream();
+			ze.export(baos);
+			ze.close();
+			String pdfContent = baos.toString("UTF-8");
+			assertFalse(pdfContent.indexOf("(via mustangproject.org") == -1);
+			// check for pdf-a schema extension
+//			assertFalse(pdfContent.indexOf("<zf:ConformanceLevel>EN 16931</zf:ConformanceLevel>") == -1);
+//			assertFalse(pdfContent.indexOf("<pdfaSchema:prefix>zf</pdfaSchema:prefix>") == -1);
+//			assertFalse(pdfContent.indexOf("urn:zugferd:pdfa:CrossIndustryDocument:invoice:2p0#") == -1);
+
+		} catch (IOException e) {
+			fail("IOException should not happen in testZExport");
+		}
+
+		// now check the contents (like MustangReaderTest)
+		ZUGFeRDImporter zi = new ZUGFeRDImporter(TARGET_PDF_FX);
+
+		// Reading ZUGFeRD
+		assertEquals(zi.getAmount(), "571.04");
+		assertEquals(zi.getBIC(), getTradeSettlementPayment()[0].getOwnBIC());
+		assertEquals(zi.getIBAN(), getTradeSettlementPayment()[0].getOwnIBAN());
+		assertEquals(zi.getHolder(), getOwnOrganisationName());
+		assertEquals(zi.getForeignReference(), getNumber());
+		
+		
+	}
+	class Contact implements IZUGFeRDExportableContact {
+		public String getCountry() {
+			return "DE";
+		}
+
+		public String getLocation() {
+			return "Spielkreis";
+		}
+
+		public String getName() {
+			return "Theodor Est";
+		}
+
+		public String getStreet() {
+			return "Bahnstr. 42";
+		}
+
+		public String getVATID() {
+			return "DE999999999";
+		}
+
+		public String getZIP() {
+			return "88802";
+		}
+
+	}
+   class Payment implements IZUGFeRDTradeSettlementPayment {
+
+		@Override
+		public String getOwnBIC() {
+			return "bla";
+		}
+
+		@Override
+		public String getOwnBankName() {
+			return "bla";
+		}
+
+		@Override
+		public String getOwnIBAN() {
+			return "bla";
+		}
+
+	}
+
+	class Item implements IZUGFeRDExportableItem {
+		public Item(BigDecimal price, BigDecimal quantity, Product product) {
+			super();
+			this.price = price;
+			this.quantity = quantity;
+			this.product = product;
+		}
+
+		private BigDecimal price, quantity;
+		private Product product;
+
+		public BigDecimal getPrice() {
+			return price;
+		}
+
+		public void setPrice(BigDecimal price) {
+			this.price = price;
+		}
+
+		public BigDecimal getQuantity() {
+			return quantity;
+		}
+
+		public void setQuantity(BigDecimal quantity) {
+			this.quantity = quantity;
+		}
+
+		public Product getProduct() {
+			return product;
+		}
+
+		public void setProduct(Product product) {
+			this.product = product;
+		}
+
+		public IZUGFeRDAllowanceCharge[] getItemAllowances() {
+			// TODO Auto-generated method stub
+			return null;
+		}
+
+		public IZUGFeRDAllowanceCharge[] getItemCharges() {
+			// TODO Auto-generated method stub
+			return null;
+		}
+	}
+
+	class Product implements IZUGFeRDExportableProduct {
+		public Product(String description, String name, String unit, BigDecimal vATPercent) {
+			super();
+			this.description = description;
+			this.name = name;
+			this.unit = unit;
+			VATPercent = vATPercent;
+		}
+
+		private String description, name, unit;
+		private BigDecimal VATPercent;
+
+		public String getDescription() {
+			return description;
+		}
+
+		public void setDescription(String description) {
+			this.description = description;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		public String getUnit() {
+			return unit;
+		}
+
+		public void setUnit(String unit) {
+			this.unit = unit;
+		}
+
+		public BigDecimal getVATPercent() {
+			return VATPercent;
+		}
+
+		public void setVATPercent(BigDecimal vATPercent) {
+			VATPercent = vATPercent;
+		}
+	}
+
+	@Override
+	public Date getDeliveryDate() {
+		return new GregorianCalendar(2019, Calendar.JUNE, 10).getTime();
+	}
+
+	
+
+	@Override
+	public IZUGFeRDExportableContact getRecipient() {
+		return new Contact();
+	}
+	
+		
+	//
+	public IZUGFeRDTradeSettlementPayment[] getTradeSettlementPayment() {
+		Payment P = new Payment();
+		IZUGFeRDTradeSettlementPayment[] allP = new Payment[1];
+		allP[0] = P;
+		return allP;
+
+	}
+
+	public IZUGFeRDAllowanceCharge[] getZFAllowances() {
+		// TODO Auto-generated method stub
+		return null;
+	}
+
+	public IZUGFeRDAllowanceCharge[] getZFCharges() {
+		// TODO Auto-generated method stub
+		return null;
+	}
+
+	@Override
+	public IZUGFeRDExportableItem[] getZFItems() {
+		Item[] allItems = new Item[3];
+		Product designProduct = new Product("", "Design (hours): Of a sample invoice", "HUR",
+				new BigDecimal("7.000000"));
+		Product balloonProduct = new Product("", "Ballons: various colors, ~2000ml", "C62", new BigDecimal("19.000000"));
+		Product airProduct = new Product("", "Hot air „heiße Luft“ (litres)", "LTR", new BigDecimal("19.000000"));
+
+		allItems[0] = new Item(new BigDecimal("160"), new BigDecimal("1"), designProduct);
+		allItems[1] = new Item(new BigDecimal("0.79"), new BigDecimal("400"), balloonProduct);
+		allItems[2] = new Item(new BigDecimal("0.025"), new BigDecimal("800"), airProduct);
+		return allItems;
+	}
+
+	public IZUGFeRDAllowanceCharge[] getZFLogisticsServiceCharges() {
+		// TODO Auto-generated method stub
+		return null;
+	}
+
+	@Override
+	public Date getDueDate() {
+		return new GregorianCalendar(2019, Calendar.JULY, 1).getTime();
+	}
+
+	@Override
+	public Date getIssueDate() {
+		return new GregorianCalendar(2019, Calendar.JUNE, 10).getTime();
+	}
+
+
+	@Override
+	public String getNumber() {
+		return "RE-20190610/507";
+	}
+
+
+
+	public String getOwnBIC() {
+		return "COBADEFFXXX";
+	}
+
+	public String getOwnBankName() {
+		return "Commerzbank";
+	}
+
+
+	@Override
+	public String getOwnCountry() {
+		return "DE";
+	}
+
+	public String getOwnIBAN() {
+		return "DE88 2008 0000 0970 3757 00";
+	}
+	
+
+	@Override
+	public String getOwnLocation() {
+		return "Stadthausen";
+	}
+
+	@Override
+	public String getOwnOrganisationFullPlaintextInfo() {
+		return "Bei Spiel GmbH\n" + "Ecke 12\n" + "12345 Stadthausen\n" + "Geschäftsführer: Max Mustermann";
+	}
+
+
+	@Override
+	public String getOwnOrganisationName() {
+		return "Bei Spiel GmbH";
+	}
+
+	@Override
+	public String getOwnStreet() {
+		return "Ecke 12";
+	}
+
+	@Override
+	public String getOwnTaxID() {
+		return "22/815/0815/4";
+	}
+
+	@Override
+	public String getOwnVATID() {
+		return "DE136695976";
+	}
+
+	@Override
+	public String getOwnZIP() {
+		return "12345";
+	}
+
+
+
+
+}