feat(objectionary#715): parse class interfaces from Xmir

src/main/java/org/eolang/jeo/representation/xmir/XmlClassProperties.java

@@ -23,6 +23,7 @@
  */
 package org.eolang.jeo.representation.xmir;
 
+import java.util.Collection;
 import java.util.Optional;
 import org.eolang.jeo.representation.DefaultVersion;
 import org.eolang.jeo.representation.bytecode.BytecodeClassProperties;
@@ -135,11 +136,29 @@ private String supername() {
  * @return Interfaces.
  */
  private String[] interfaces() {
- return this.clazz.xpath("./o[@name='interfaces']/o/text()")
- .stream()
- .map(HexString::new)
- .map(HexString::decode)
- .toArray(String[]::new);
+ return this.clazz.optchild("name", "interfaces")
+ .map(
+ node -> node.children()
+ .map(XmlValue::new)
+ .map(XmlValue::bytes)
+ .map(XmlBytes::hex)
+ .map(HexString::decode).toArray(String[]::new)
+
+ ).orElse(new String[0]);
+
+// return
+// .flatMap(node -> node.children())
+// .map(XmlValue::new)
+// .map(XmlValue::bytes)
+// .map(XmlBytes::hex)
+// .map(HexString::decode)
+// .orElse(new String[0]);
+//
+// return this.clazz.xpath("./o[@name='interfaces']/o/text()")
+// .stream()
+// .map(HexString::new)
+// .map(HexString::decode)
+// .toArray(String[]::new);
  }
 
  /**