@Nullable
    @Override
    public <R, C> R accept(Visitor<R, C> v, @Nullable C context) {
        return query.accept(v, context);
    }
Default implementation of the Union interface

@param <T> result type
@param <Q> concrete query type

@author tiwe
querydsl-sql/src/main/java/com/querydsl/sql/UnionImpl.java