@Test
    void Optional_CloudKey_ValuePresent_ReturnsValue() {
        // Arrange
        this.context.store("foo", "bar");

        // Act
        final Optional<String> result = this.context.optional(cloudKey("foo", String.class));

        // Assert
        assertThat(result).hasValue("bar");
    }
Tests for {@link CloudKeyContainer} using {@link CommandContext}.
cloud-core/src/test/java/org/incendo/cloud/key/CloudKeyContainerTest.java