public void iteratorDef() {
    // find type id and colln on the stack

    ObjectType type = assembleType(); // can be null
    CompiledID id = TypeUtils.checkCast(pop(), CompiledID.class); // can be null
    CompiledValue colln = TypeUtils.checkCast(pop(), CompiledValue.class);

    if (type == null) {
      type = TypeUtils.OBJECT_TYPE;
    }

    push(new CompiledIteratorDef(id == null ? null : id.getId(), type, colln));
  }
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