@Override
    public FactoryExpression<T> getProjection() {
        if (projection == null) {
            projection = RelationalPathUtils.createProjection(this);
        }
        return projection;
    }
Compares the two relational paths using primary key columns

@param right rhs of the comparison
@return this != right
querydsl-sql/src/main/java/com/querydsl/sql/RelationalPathBase.java