Implement missing eperimental variable functionality

application-commons/src/main/java/life/qbic/application/commons/CanSnapshot.java

@@ -0,0 +1,45 @@
+package life.qbic.application.commons;
+
+/**
+ * Interface to implement the Memento/Snapshot pattern. <a
+ * href="https://refactoring.guru/design-patterns/memento">Memento Pattern</a> Originators of
+ * Mementos or Creators of Snapshots should implement this interface.
+ */
+public interface CanSnapshot {
+
+  /**
+   * Capture the internal state and expose it as a Snapshot.
+   *
+   * @return the created snapshot
+   */
+  Snapshot snapshot();
+
+  /**
+   * Adapts the internal state to match the information provided by the snapshot. The method can
+   * fail throwing a {@link SnapshotRestorationException} for unknown types of Snapshots.
+   * <p>
+   * It is the responsibility of the implementation to make sure after successful application or
+   * failure, the internal state of the object is valid.
+   * <p>
+   * After snapshot restoration failure. The object is expected to revert all modifications made by
+   * the attempt.
+   *
+   * @param snapshot the snapshot to be restored
+   * @throws SnapshotRestorationException thrown when snapshot restoration failed.
+   */
+  void restore(Snapshot snapshot) throws SnapshotRestorationException;
+
+  /**
+   * Indicates that a snapshot cannot be used to restore the state of the originator.
+   */
+  class SnapshotRestorationException extends RuntimeException {
+
+    public SnapshotRestorationException(String message) {
+      super(message);
+    }
+
+    public SnapshotRestorationException(String message, Throwable cause) {
+      super(message, cause);
+    }
+  }
+}

application-commons/src/main/java/life/qbic/application/commons/Snapshot.java

@@ -0,0 +1,11 @@
+package life.qbic.application.commons;
+
+import java.io.Serializable;
+
+/**
+ * Interface for the Memento in the <a
+ * href="https://refactoring.guru/design-patterns/memento">Memento Pattern</a>
+ */
+public interface Snapshot extends Serializable {
+
+}

project-management/src/main/java/life/qbic/projectmanagement/application/VariableValueFormatter.java

@@ -1,5 +1,7 @@
 package life.qbic.projectmanagement.application;
 
+import static java.util.Objects.nonNull;
+
 import life.qbic.projectmanagement.domain.model.experiment.ExperimentalValue;
 
 public class VariableValueFormatter {
@@ -15,7 +17,17 @@ private VariableValueFormatter() {}
    * present
    */
   public static String format(ExperimentalValue experimentalValue) {
-    String optionalUnit = experimentalValue.unit().map(unit -> " " + unit).orElse("");
-    return experimentalValue.value() + optionalUnit;
+    return format(experimentalValue.value(), experimentalValue.unit().orElse(null));
+  }
+
+  /**
+   * Formats the value and unit strings according to a standard format for experimental values.
+   *
+   * @param value the value
+   * @param unit  the unit
+   * @return a String representation
+   */
+  public static String format(String value, String unit) {
+    return value + (nonNull(unit) ? " " + unit : "");
   }
 }