@Override
    public void addJoinFlag(JoinFlag flag) {
        throw new UnsupportedOperationException();
    }
{@code EmptyMetadata} provides an immutable empty {@link QueryMetadata} instance.

<p>Modification methods throw {@link UnsupportedOperationException}.</p>

@author tiwe
querydsl-core/src/main/java/com/querydsl/core/EmptyMetadata.java