package poussecafe.util;

public class StringKey {

    private String id;

    public StringKey(String value) {
        id = value;
    }

    public String getValue() {
        return id;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((id == null) ? 0 : id.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        StringKey other = (StringKey) obj;
        if (id == null) {
            if (other.id != null) {
                return false;
            }
        } else if (!id.equals(other.id)) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return id;
    }
}

@@ -19,16 +19,71 @@
 .util;%0A%0A
+import static poussecafe.check.Checks.checkThatValue;%0A%0A
 public c
@@ -157,24 +157,65 @@
 ng value) %7B%0A
+        checkThatValue(value).notNull();%0A
         id =

Add missing check on StringKey.