Direct Debit: add field CreditorReferenceID.

library/src/main/java/org/mustangproject/DirectDebit.java

@@ -0,0 +1,42 @@
+package org.mustangproject;
+
+import org.mustangproject.ZUGFeRD.IZUGFeRDTradeSettlementDebit;
+
+/**
+ * provides e.g. the IBAN to transfer money to :-)
+ */
+public class DirectDebit implements IZUGFeRDTradeSettlementDebit {
+	/**
+	 * Debited account identifier (BT-91)
+	 */
+	protected final String IBAN;
+
+	/**
+	 * Mandate reference identifier (BT-89)
+	 */
+	protected final String mandate;
+
+	/***
+	 * constructor for normal use :-)
+	 * @param IBAN the IBAN as string
+	 * @param mandate the mandate as string
+	 */
+	public DirectDebit(String IBAN, String mandate) {
+		this.IBAN = IBAN;
+		this.mandate = mandate;
+	}
+
+	/***
+	 * getter for the IBAN
+	 * @return IBAN
+	 */
+	@Override
+	public String getIBAN() {
+		return this.IBAN;
+	}
+
+	@Override
+	public String getMandate() {
+		return this.mandate;
+	}
+}