private LinkedHashMap<Integer, CompiledAggregateFunction> identifyAggregateExpressions(
      final List<Object[]> projAttribs) {
    if (projAttribs != null) {
      final LinkedHashMap<Integer, CompiledAggregateFunction> mapping = new LinkedHashMap<>();
      int index = 0;
      for (Object[] o : projAttribs) {
        CompiledValue proj = (CompiledValue) o[1];
        if (proj.getType() == OQLLexerTokenTypes.AGG_FUNC) {
          mapping.put(index, (CompiledAggregateFunction) proj);
        }
        ++index;
      }
      return mapping.size() == 0 ? null : mapping;
    } else {
      return null;
    }
  }
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