TEST(QueryProjectionTest, InclusionProjectionPreservesField) {
    auto proj = createProjection("{}", "{a: 1}");
    ASSERT_TRUE(proj.isFieldRetainedExactly("a"));
}
TEST(QueryProjectionTest, InclusionProjectionPreservesField) {
    auto proj = createProjection("{}", "{a: 1}");
    ASSERT_TRUE(proj.isFieldRetainedExactly("a"));
}