@brief The _distanceTo function returns all paths and there distance within a graph.

`graph._distanceTo(startVertexExample, endVertexExample, options)`

This function is a wrapper of [graph._shortestPath](#shortestpath).
It does not return the actual path but only the distance between two vertices.

@EXAMPLES

A route planner example, shortest distance from all german to all french cities:

@EXAMPLE_ARANGOSH_OUTPUT{generalGraphModuleDistanceTo1}
  var examples = require("@arangodb/graph-examples/example-graph.js");
  var g = examples.loadGraph("routeplanner");
| g._distanceTo({}, {}, {weight : 'distance', endVertexCollectionRestriction : 'frenchCity',
  startVertexCollectionRestriction : 'germanCity'});
~ examples.dropGraph("routeplanner");
@END_EXAMPLE_ARANGOSH_OUTPUT

A route planner example, shortest distance from Hamburg and Cologne to Lyon:

@EXAMPLE_ARANGOSH_OUTPUT{generalGraphModuleDistanceTo2}
  var examples = require("@arangodb/graph-examples/example-graph.js");
  var g = examples.loadGraph("routeplanner");
| g._distanceTo([{_id: 'germanCity/Cologne'},{_id: 'germanCity/Munich'}], 'frenchCity/Lyon',
  {weight : 'distance'});
~ examples.dropGraph("routeplanner");
@END_EXAMPLE_ARANGOSH_OUTPUT