anchor.diff:  |===
   | Name | Default value| Description
   
  -| `path`             | {es} index/type    | _required_
  +| `path`             |  _required_        | {es} index/type
   | `pushdown`         | `true`             | Whether to translate (__push-down__) Spark SQL into {es} Query DSL
   | `strict`           | `false`            | Whether to use _exact_ (not analyzed) matching or not (analyzed)
   
  
positive.code: 
  val sql = new SQLContext(sc)
  
  val people = sql.esDF("spark/people") <3>
  
  // check the associated schema
  println(people.schema.treeString)             <4>
  
negative.code: [source,java]
  ----
  import org.apache.spark.sql.api.java.JavaSQLContext;          <1>
  import org.elasticsearch.spark.sql.java.api.JavaEsSparkSQL;   <2>
  ...
  SQLContext sql = new SQLContext(sc);
  
  