invoke(jobj, method, ...)
invoke_static(sc, class, method, ...)
invoke_new(sc, class, ...)spark_jobj).spark_connection.| invoke | Execute a method on a Java object reference (typically, a spark_jobj). | 
| invoke_static | Execute a static method associated with a Java class. | 
| invoke_new | Invoke a constructor associated with a Java class. |