class VersionReference {

	private final VersionProperty property;

	private final String value;

	private VersionReference(VersionProperty property, String value) {
		this.property = property;
		this.value = value;
	}

	public static VersionReference ofProperty(VersionProperty property) {
		return new VersionReference(property, null);
	}

	public static VersionReference ofProperty(String internalProperty) {
		return ofProperty(VersionProperty.of(internalProperty));
	}

	public static VersionReference ofValue(String value) {
		return new VersionReference(null, value);
	}

	/**
	 * Specify if this reference defines a property.
	 * @return {@code true} if this version is backed by a property
	 */
	public boolean isProperty() {
		return this.property != null;
	}

	/**
	 * Return the {@link VersionProperty} or {@code null} if this reference is not a
	 * property.
	 * @return the version property or {@code null}
	 */
	public VersionProperty getProperty() {
		return this.property;
	}

	/**
	 * Return the version of {@code null} if this reference is backed by a property.
	 * @return the version or {@code null}
	 */
	public String getValue() {
		return this.value;
	}

	@Override
	public boolean equals(Object o) {<FILL_FUNCTION_BODY>}

	@Override
	public int hashCode() {
		return Objects.hash(this.property, this.value);
	}

	@Override
	public String toString() {
		return (this.property != null) ? "${" + this.property.toStandardFormat() + "}" : this.value;
	}

}

		if (this == o) {
			return true;
		}
		if (o == null || getClass() != o.getClass()) {
			return false;
		}
		VersionReference that = (VersionReference) o;
		return Objects.equals(this.property, that.property) && Objects.equals(this.value, that.value);
	
<no_super_class>