public void compileImports(String imports) {
    try {
      OQLLexer lexer = new OQLLexer(new StringReader(imports));
      OQLParser parser = new OQLParser(lexer);
      // by default use Unsupported AST class, overridden for supported
      // operators in the grammar proper
      parser.setASTNodeClass("org.apache.geode.cache.query.internal.parse.ASTUnsupported");
      parser.loneImports();
      GemFireAST n = (GemFireAST) parser.getAST();
      n.compile(this);
    } catch (Exception ex) {
      // This is to make sure that we are wrapping any antlr exception with Geode Exception.
      throw new QueryInvalidException(format("Syntax error in query: %s", ex.getMessage()), ex);
    }
    Assert.assertTrue(stackSize() == 0, "stack size = " + stackSize() + ";stack=" + stack);
  }
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