@brief Returns the number of returned elements if the query is executed.

`graph_query.count()`

This function determines the amount of elements to be expected within the result of the query.
It can be used at the beginning of execution of the query
before using *next()* or in between *next()* calls.
The query object maintains a cursor of the query for you.
*count()* does not change the cursor position.

@EXAMPLES

To count the number of matched elements:

@EXAMPLE_ARANGOSH_OUTPUT{generalGraphFluentAQLCount}
  var examples = require("@arangodb/graph-examples/example-graph.js");
  var graph = examples.loadGraph("social");
  var query = graph._vertices();
  query.count();
~ examples.dropGraph("social");
@END_EXAMPLE_ARANGOSH_OUTPUT