public void projection() {
    // find an id or null on the stack, then an expr CompiledValue
    // push an Object[2] on the stack. First element is id, second is CompiledValue
    CompiledID id = pop();
    CompiledValue expr = pop();
    push(new Object[] {id == null ? null : id.getId(), expr});
  }
Processes import statements only. This compiler instance remembers the imports and can be used
to compile other strings with this context info
geode-core/src/main/java/org/apache/geode/cache/query/internal/QCompiler.java